I can't say what's right for YOU to do, but I can share my story.
When I became pregnant that was the catalyst to make my decision to sell my then mare AND search for and buy a horse better suited to me. But in that case I hadn't ever properly bonded with my mare - it was a decision that needed to be made anyway.
When I was buying my gelding he was out on loan when I met him and I didn't actually meet the owner until we exchanged money and papers. I had failed to mention my pregnancy over the phone as I was worried that he wouldn't sell his horse to a pregnant lady!
So - that is the third option - sell AND buy now.
My brother asked me why I was buying while pregnant "surely it would be easier to wait?". I explained that I knew that if I waited till I'd had the baby, and got though tiny baby-hood.......then in reality it might be years before I actually got back into horses.
For me, THAT was the right decision to make.