pregnant after mc??

Lauren
Hi guys! Sorry in advance if this is lengthy. I'm hoping whoever is reading this can give me some answers or success stories. Ok, so last month I had a mmc at 6w. We went in for a scan and there was no heartbeat. I opted to take medication to induce mc. After a week or so I got my blood drawn and dr confirmed no more testing was needed to monitor hcg. When I stopped bleeding from mc my husband and I had sex. One week ago, I took a pg test and it clearly came out negative. I took another one a few days ago and I had a positive! The next day I took another one and it was darker. Today I took these and I got 2-3 weeks on the weeks estimator! My concern is that I don't feel pregnant and I started lightly spotting brown for about 4 days now. Could the spotting be left over blood from mc? Or leftover IB? I have no cramping. Anyone have any ideas what's going on!?!