not sure what to think- need advice...

I had a d&c on 2/17, only had bleeding for one day and was given the all clear soon after. Had a super positive opk on 3/17 and did a good amount of bd around then. Had 1 day of spotting/very light flow last Wednesday. Since Monday I've had mild low cramping and have been super tired and not too hungry. I've taken a few hpts that I'm pretty sure were negative (or had a vvvfl) but I also took an opk today for the hell of it and it had a visible line but not as dark as control.  Don't understand what could be going on at this point... thoughts/advice???