Can you feel it?

Well DH finally agreed to TTC our second! YAY!!! So for the first time in my life I learned about my own fertility and we worked out the schedule for this month. It took me forever to get my AF back after my ds was born (2 1/2 years, actually!!) and now I've had it 3 times but the time between has gone from 45 days, to 40 days, to 31 days most recently. So it's been a little hard to figure out exactly when I'm supposed to be most fertile.

I didn't want to take any chances on missing my O so we have been keeping busy trying to cover all the bases, so to speak

Anyway, what I wanted to ask my fellow MDC'ers about is, last night I felt some things happening in my lower abdomen... This week is supposed to be my most fertile time. I'm wondering if maybe I am feeling implantation? I know some women feel their own ovulation happening, and honestly I've never paid attention to any of this much before, but this feels sort of like a tug or something. I'm not sure how to describe it.

And, yes, I could just be patient and wait a couple of weeks to take a test, but I'm SO EXCITED!!!

So - has anyone out there been able to tell if conception has taken place, strictly based on physical sensations alone?