My balloon molly just drop fry but looks like she is getting more pregnant. Why?

I bought a pregnant balloon molly four days ago and she dropped four fry two hours after putting her in the new tank. I was shocked by how small the amount of fry was and how quickly she had them after being put in the tank, but I thought maybe it was just a small load and odd timing. Recently, however, she has been getting larger, as if she is getting further along in her pregnancy. Is it possible that the shock of moving to a new tank caused her to prematurely release some fry, and she will drop a larger amount soon? I want to save all the fry I can, but I also don't want to put her in a breeding chamber if it isn't necessary. Thanks!