Miscarriage/TTC Question

I had an early miscarriage July 4th. It was hard on us. Dr told us to wait one cycle before trying again. So that's what we are trying to do. Not sure when AF should show after miscarriage, but we did BD twice this month (didn't think they were around ovulation) Starting yesterday I have really sore chest and today started having headaches. These were two of the symptoms I had before. Not sure what to think? I Guess it's possible I could be pregnant again. Has this happened to anyone else?  Has anyone had a successful pregnancy right after miscarriage? How long does it take for AF to show? I'm a bit worried and concerned. Thoughts, opinions, advice please.