Yes, if your cervix is open and you're ovulating your chances of pregnancy are much higher. MY peri dr said the 1st 3 months after pregnancy loss is more fertile and that has to do with your cervix still being slightly open. So if you're not supposed to be TTC because of medical reasons I would continue to use condoms or a diaphram.
BUT....
I would talk to your doctor about the "what if's" if you get pregnant any time soon and that might make you feel a little better about it. That way if you don't use protection every time you won't be so afraid of the "what if's"
Hope this helps ya