Bleeding

Hey there.  I don't post very often but often read and follow other posts.  My husband and I have a 13 month old boy that we conceived through IVF.  We were hoping not to have to do IVF again to get #2 so we started trying as soon as our doctor gave us the all clear but no such luck.  This past spring we did two IUIs and got 2 BFNs of course.  We then took a break over the summer to save up some money.  After my last IUI my period won't come back on it's own.  I did a round of Provera and it came back after that.  Well another 11 weeks go by and still no period.  My doctor's office is doing a new method in the sperm washing for the IUI so we are going to give it one more shot this fall.  Well they put me on birth control to get my estrogen level up and then when period starts we will start meds to do the IUI.  However after my husband and I have had sex I will start bleeding probably 3 out of the past 5 times.  We aren't doing anything wild and crazy and it isn't causing me any pain.  I started week two of my pills yesterday and after sex on Sunday I was bleeding a lot, and then started bleeding again yesterday for no reason.  My doctor wants to do a u/s tomorrow morning to check things out but has anyone else had anything like this happen???  Thanks and good luck to everyone!