Am I having a miscarriage?

Ok here are the details. Sunday, I took 4 pregnancy tests (all came up positive), Monday I had bloodwork done which confirmed I was around 5 weeks pregnant, Tuesday I had a little blood when I wiped, I immediately went to my OBGYN which did a l ultrasound. The baby was in there, in the correct place, sitting up high. He told me since it's so early, he can't really tell me anything else except to take it easy. Wednesday, there was a dime-sized amount of brown discharge on my underwear (called nurse again and she said that it was probably just old blood) Nothing yesterday, no blood or brown. Today there was a tiny amount of blood when I wiped. This is also the time of my period. I didn't have a period at all last month, but this is the time frame it would be in this month. Someone please help me and tell me there's someone out there that's been through this. Am I losing my baby?