Brown ovulation during pregnancy?

i am 7 weeks pregnant and today when i wiped after using the restroom i noticed a slimy substance what would normally be an ovulation ...however, it was brownish...my fiance and i had sex last night so i'm not sure if that is what has caused it. i am very careful with everything because i am RH negative and my doctor told me the first sign of bleeding go to the ER. im kind of worried and everything...please let me know :) thank you in advance!!