Thank you Annie.. I was also on the suppositories up to 8 weeks and then I was taken off and went from the nightly prog shot to the weekly. I agree, I believe the cramps are my bodies response to the drop in prog. I will ask if I can go back on the suppositories until the placenta takes over. These cramps are just so scary since I associate the pain with bleeding. Thanks for the advice and good luck to you as well.
I think I would ask if you could be prescribed a progesterone suppository, to be inserted daily or two times a day. (This could be along with your usual shot.) Progesterone doesn't last very long in your system, and it seems quite feasible that your shots aren't lasting long enough. They give the shots largely because those are measureable in the blood and the suppositories apparently aren't as reliably measureable, but the suppositories do keep your uterine lining where it is supposed to be if it might otherwise leave you in the early weeks of IVF due to of lack of progesterone.
Because progesterone doesn't last very long in your system, my clinic had me on a progesterone shot every day (that painful one in sesame oil) until at least week 11. They started me on suppositories at about week 9 to back it up, and then tapered me off the shots over a few weeks. Then I was on the suppositories for several more weeks. They kept me from losing my lining due to lack of progesterone. (Note that if I had been miscarrying, progesterone would not be enough to stop it.)
I would talk seriously to your doctor about this tomorrow, since it can't hurt you or the pregnancy to take the suppositories. My suppository dose was twice daily for a while, then once daily, after the main risk of miscarriage was over. By now (week 18) the placenta is producing all the progesterone I need, and so I don't take them any more.
As far as whether the cramping will hurt your baby, no. Only if you get such a drop in progesterone that it causes the whole lining of the uterus to slough off, baby and all. (And even then, the baby might still "stick.") Cramping alone does not have an effect on the baby. (The only time there would be a connection is if the cramping is coming from a miscarriage, but that doesn't sound like what is happening here.)
And as far as your cervix holding back a bunch of blood, nope. If you are going to bleed, it comes out. The cervix is still considered "closed," but it will let blood out.
I had a "vanished twin" at 8-plus weeks, and had bleeding with it, and still didn't lose the other baby, and all of these answers I am giving about the effect of progesterone in IVF are from asking the doctor these things during that time.
Good luck, honey! IVF is so funny -- these pregnancies are so difficult to create and so fragile in the first 13 weeks that it can seem like you can never sit down on the chair with your full weight in case it might break! But it sounds like you'll get there, just keep your attention up and ask your doctor for sound medicine.
(((HUGS)))
Annie