Riverview: Aside from exhaustion the first trimester, I didn’t feel pregnant! Didn’t have nausea/vomiting until the second trimester (I know, weird). I started to look more and more bloated, but probably didn’t “feel” really pregnant until I started feeling the baby move. I was more cautious while riding because I knew I was pregnant. I hated being pregnant actually, but I may be in the minority for that. :lol: I was in my second trimester during the entire humid MD summer and had 5 horses at home. I take a medication that can cause you to sweat less and be more prone to heat stroke, plus I was anemic. Not fun! I got tired very quickly doing chores, but didn’t have any help so had to push through. It was very embarrassing when I almost passed out holding my horse for the farrier and he had to give me one of his cold gatorades. :o It didn’t help matters that my SO didn’t want me to overdo it, but wouldn’t exactly help out either. On the other hand, SO’s father constantly told me to slow down and not overdo it (which was sometimes annoying to a hormonal prego lady when I wasn’t receiving help but maybe everything was just annoying!). Definitely stay active if you can, but don’t be afraid to let your SO help you out if he offers! Let yourself be pampered. 
Now, as for the riding part. I rode my two TB’s (and continued mucking stalls at the boarding barn) normally during the first trimester. I tried to show both of them at 12ish weeks pregnant in June, but the young one was a nut so we only schooled (turns out he had ulcers and can’t handle alfalfa hay) and the older one doesn’t do well in the heat- he was super strong to school in the morning, then by the time our classes ran in the hottest part of the day, he was zapped out and was hitting rails (normally overjumps everything) so we scratched. The rest of the summer I only had the energy to get on my younger (now sane again) TB for ten minutes because he’d happily w/t/c on the buckle. I didn’t ride my older horse because he’s a strong, tough ride and occasionally is set off by nothing, and while I’m normally fine with him (have owned him 7+ years), I didn’t want to risk it when I wasn’t “all there” physically and mentally. At that point, I didn’t feel off-balance, but my leg was weaker, probably from not riding nearly as much as I had for years. I went cross-country schooling on my younger TB when I was 6 months pregnant (baby was actually kicking a lot during our school!) and did a local horse trial at 7 months pregnant. I only did the intro level though because that particular horse still needed a strong ride at the canter for a dressage test and I no longer had the abdominal muscles to do more than ride in a light or half seat at the canter. 
I rode here and there during the 3rd trimester and never felt off balance but stopped mostly because I couldn’t get off my horse without assistance! :lol: The last time I rode longer than 10-15 minutes was when I went trail riding on a gorgeous fall day. I rode in maternity jeans and my SO’s big, comfy, broken-in western saddle. Had I been in my second trimester during the fall, I would have ridden far more! It was the heat that prevented more riding, and I had them at home so no lights to ride in the cooler evening hours.
I stayed small throughout my first and second trimesters and gained mostly in the third trimester. I fit just fine in my regular breeches throughout the first trimester and part of my second (I actually lost weight for a while) and then was able to just use a rubberband on the snap of my breeches to allow a bit more room around 6 months. My tights didn’t feel comfortable but my yoga pants and leggings were ok with half chaps to have short hacks at home. For the horse trial at 7 months, I had to buy a bigger pair of breeches and coat. They didn’t exactly look gorgeous since the legs were too baggy, but oh well. If you aren’t showing, I would just try to use comfy leggings/yoga pants or maternity jeans rather than buy new breeches.
My Ob-gyn’s daughter showed hunters on the A-circuit so she has a good understanding of horse people and okay’d me to continue riding. My SO was not too supportive of it though.
As far as riding after delivering you little one(s), just depends on how you’re recovering, what your doctor says, and the time you have. I have 5 horses at home and it was SO HARD in those first few weeks to just get the barn chores done! Granted, I had my DS at the beginning of the past December, so we had blanket changes, more stall cleaning than normal, and heated buckets to keep filling vs. the bigger trough, but still, you don’t realize how EXHAUSTING a baby is until you have one! Also didn’t help that I’m breastfeeding so I was the one up all hours of the day and night and had to be there for him to eat (which was literally almost 24/7 the first couple weeks!), and my SO didn’t take off work, and he expected me to continue doing barn chores AM & PM immediately after I got home from the hospital so he didn’t have to get up an extra 15 minutes early for work…but that’s a rant for another day. Luckily I had an easy delivery and felt fine to ride about 4 weeks later, but my DS is 10.5 weeks and I’ve only been able to ride for maybe 10 minutes tops 3 times (solely because SO doesn’t give me the opportunity to go out and do something for myself, and the ground is frozen). Seriously, I don’t know how some mom’s manage to go out and ride so early on! Maybe they’re formula feeding so someone else can do it, or maybe they introduce a bottle with pumped milk earlier than I did, or maybe they have better facilities, or had their LO at a better time of the year, or maybe a more supportive SO? I’d LOVE to, but unfortunately it isn’t happening right now. Oh, and I lost all of my weight VERY quickly (thanks to nursing!) but don’t have nearly the same amount of muscle for riding. 
Hopefully you were able to pull some useful info out of that long, rambling post. 
Congrats!!!
