blood clot

So im 6 weeks pregnant and for 2 days ive had brown spotting not much at all. Went to my doctors because I was scared he told me it looks like a blood clot and he can see the start of the babys heartbeat. Ive never had a blood clot with my last so im new to this. He told me to take one baby aspirin a day and wants to see me back in a week? Have any of you ladies experienced this? Help girls