Worried

I had a little girl july 10th, born 2 weeks early with the help of a c section. I KNOW I'm supposed to wait 6 weeks before having sex but my husband and I got carried away one night seeing as 5 months Into my pregnancy I lost all interest in sex of any sort and I was just curious before taking a pregnancy test how likely it is that I could be pregnant. I breastfed for the first 2 weeks of her being born and then stopped and that's about the time we had sex... recently my scar started hurting/burning and I've had a little bit of brown discharge kinda like implantation.