TTC after c-section

Jessica
Let me preface by saying I'm not TRYING to conceive at the moment. My heart and body want another baby, but my mind knows my body needs time to heal after my c-section five months ago. But I'm thinking about starting to try in the next few months. 
Now, here's where it gets a bit messy. My husband and I had unprotected sex at the very beginning of my fertility window. My period has been very regular post-partum, so I trust my charted cycle. The chances of conception are low but not zero. 
Anyway, today I'm about four days past my ovulation date. I am experiencing some cramping. It's more than ovulation pain... more painful and lasting longer. Not painful enough to make me call a doctor, but noticeable. It's too soon to be a period (and also too soon to take a pee test). Could this be implantation cramping? There was very minor spotting in my cervical fluid.
I feel like it's either implantation or my uterus is still healing after the surgery so maybe some cramping during my cycle is to be expected. Anyone experience anything similar? Thanks!