Fig, i'm 13 weeks and 1 day pregnant. I had bleeding on Christmas night, it was a massive gush (tmi) and I went to emergency who did blood test and it was all ok so had an ultra sound the next day and baby was good - strong heart and the right size etc. The bleeding stopped after a week and was mainly brownish (old blood). The lady who did the ultrasound said sometimes there is no explaination for it. In my case she could see some hemroging (sic) at the top of the sack but wouldn't pin point that as the reason. Everything has settled down now and my 12 week scan was great. Everything going to plan. I thought the same as you, that i was m/c but have since found out it is very common to bleed during pregnancy. Goodluck and i hope things turn out positive for you.