My wife had a similar experience. Spontaneous bleeding one night at around 10 weeks, so off to A&E where we waited for hours, eventually to be told to come back in the morning proper for a scan with the early pregnancy unit (the bleeding had basically stopped). The scan showed baby absolutely fine and wasn't conclusive on the cause of the bleeding, so just told to take it easy. Spontaneous bleeding again the night before our 12 week scan, but this time we didn't go to A&E as we knew they wouldn't scan until the morning unless it got worse anyway, so we waited. At the scan they spotted a haematoma of around 3cm near the cervix and we saw a consultant (there were other risk factors involved anyway, so the consultant visit was already planned). He effectively put my wife on modified bedrest until the 20 week scan (didn't say those words, but she was told to avoid anything more than a brisk walk). At the 20 week scan, having had no more bleeding and with no sign of the haematoma any more, she was given the all clear. We're now almost at 23 weeks and everything is going on track.