Am I still fertile this long after a miscarriage? Could I be Pregnant?

I had a miscarriage going on 9 weeks ago (Feb 23). I have taken pregnancy tests just to see if it would still say I was pregnant. It has said negative for the last few weeks. I have yet to start my cycle so I am trying to be careful when my husband and I have sex, but a couple of time we didn't use protection. I know, I know, shame on me. He didn't ejaculate though, if that matters. I wasn't sure how long I would be at this state of fertility.

I was wondering cause I thought I saw bleeding one day but it was gone the next. It was darker and very light. Wasn't sure if that was implantation or just my body getting ready to ovulate. I've been wanting all kinds of sweets and breaking out really bad. My boobs are also a little tender. But I have had them get that way before a period too. We're not trying to concieve cause I'm still a little scared that history might repeat itself. I couldn't deal with that right now. Any ideas of what could be going on? My doctor doesn't seem to think much of anything but I didn't like that answer. So that's why I'm asking you. Any input would be great. Thanks in advance.