This is a very personal choice. I will just share my experience with you, which is vastly different from yours.
I got pregnant after the very first try and it has been smooth sailing, no sickness at all. I basically feel exactly the same as pre-pregnancy, except I am getting larger. I have never had a miscarriage or trouble conceiving and personality wise, I am not a “mom type”.
I am 24 weeks pregnant and until this past week, I was riding every day and continued to jump, I showed in the jumpers on my horse who is not quiet, but at the same time I feel very comfortable on her, she is very much my ride and I never ever felt at risk (or any moreso than any other ride of my life). As an aside, my horse is also much easier and relaxed when jumps are involved, flatting seems to allow for mind wandering and spooks, while jumping or work over poles really gets her focus, she is also much better at the shows than at home. Before this pregnancy, my goal was to end the year with her in the 1.15-1.20 meter, we had been successful over the winter in the 1.05 and I moved her up to 1.10 in the spring and was successful. The original goal for last week’s show was to be in the High Adult Jumpers (1.10-1.15), however, due to the pregnancy, we dropped back and did the Low Adult Jumpers (1-1.05) and had a successful show. I admit, I am bummed about not reaching the horse goals this year, but I also think a move up at this time would have been a bit foolhardy. My husband was as supportive as he could have been, he is not a horse person and in general sees horses as money pits. My trainer and other immediate family members also were supportive but cautious. Everyone agreed that this weekend’s show would be the last. So, that was my plan and I stuck with it and never felt at risk, we were well within our comfort level and the venue was a familiar one for us.
My doctor was not enthusiastic about my riding, but she really felt that after viability (24 weeks) it was time to stop. So, while I feel that continuing to ride would be less risky than walking through the sketchy parking garage after work, I have stopped, because on the off chance something were to occur, I would feel pretty terrible.
For the rest of my pregnancy, I will be heading over to the barn 4 times/week and doing lunging and ground work, try to fill in some little gaps in her training if I can, and hope to get back to business over the winter, so no more riding for me, but I plan on keeping her going as I can, and also for my sanity.
My approach has been pretty cavalier compared to a lot of women and I think that may be because everything has been very easy for me, if I had suffered a loss of a much hoped for child, I may not have continued as long as I did, or I may have stuck to mostly flatwork on quieter horses than my own.
Whatever you decide, I encourage you to continue at the barn in general, lunging, grooming, just hanging out so you get some horse time and still feel connected. There are other goals you can work toward without being in the saddle and the barn family is a great one for general support, so either way, don’t leave the horses completely!