Spotting Yet...

I noticed a few days ago that I was "smudging" or "spotting". It was accompanied by cramping on the left side, a sensation akin to typical ovulation pain or what you might feel from an ovarian cyst, and a bunch of fertile CM. I made note in an earlier post that if I didn't know better, that I'd think I was ovulating. Tonight I'm seeing that the spotting has increased quite a bit. It's a bit disturbing as this didn't happen in my last/first IVF cycle.

I googled this and most sources say that this can be natural for people starting out on BCPs, but I also found a bunch of references that say it can be from taking pills that aren't strong enough, or from missing a pill. I'm taking the exact same pill I took in the last cycle, so it's not that it's not strong enough for me...and I haven't missed a single pill...so I'm not sure what is up with my body. Wikipedia says that breakthrough bleeding can be from an excessively thick endometrium. That sounds like a positive thing to me. A thick lining is something I want for transfer, so a thicker lining means a better chance of implantation? Yeah, so it's a bit early for my lining to be thick *now*, but maybe my body is going to behave differently this cycle?

I have fired off an email to the "in cycle nurses" and hope they get back to me with an answer that is reassuring rather than stress producing. If any of you have any knowledge about this I would love to hear from you.