Lets take this image and analyse it:
-Your whole body is out of focus, including your baby belly which is the superstar of the show, you can clearly see that the red metal tube you are holding is what got in focus.
-Hair and make up could be better, heavy make up does not favour the whole image of "pregnancy shoot", a more natural approach should suit the images better in my opinion. The hai even though it is curled on the sides, the top looks just left uncared for.
-Like everyone has pointed out the heavy patterns on the clothing doesn't help either.
-Just in general, lighting is bad, there are too many distractions (patterns, foreground, bad hair and make up, important elements out of focus and the SUPER ANNOYING WATERMARK), I'm not saying that every pregnancy image has to be a cliché one but there are technical elements that need improvement BIG TIME.
-Try with solid colours, white and black work really well, I've seen some shots that have the belly uncovered and the mum is wearing a natural skin colour bra, no need to go nude for it to look nice, simple backgrounds would work great, don't forget that the main emphasis has to be your belly! Not everything else around it.
I would suggest trying different photographers and make a deal where you get unwatermarked images. Like some else mentioned: quality not quantity.
Hope that helps and congratulations on your pregnancy!