If you just spot a little that is fine, it happens a lot but if you have blood like if it was your period, then go to ER for them to check hormones and u/s... Good luck !
When I was 10 weeks, I was spotting brown blood for two weeks straight with mild cramping In the beginning. I called the Doc. and asked to come In juss to make sure everything was okay. Turned out baby was fine. I would call and ask to make an appt. If It continues to be on the safe side 'cuz like Ktowne has said, It can be many things and If It's somethin' not very good, they might be able to fix It now while It's early. Not trying to scare you or anything.
I would call your doctor and get some advice, or go to the ER. You want to check out why you're bleeding at this stage it could be many things, even an infection can cause spotting. If you go and get checked out and it's just an infection then you won't have to stop working or anything, if it's something more serious, bedrest might be your only option. Good luck hun!