Miscarriage 2 wks ago, u/s normal-very slight brown spotting. how high is chance of infection if i start having sex? some say ok to start right away

Low: the brn discharge means that the path to uturus is still open slightly but risk is low. To be extra cautious, wait until discharge stops.

Okay: You should be fine to engage. I say this assuming that your unfortunate miscarriage was not complicated but straight forward.

Low: It is better to wait for a week after an abortion before engaging in sexual relations if you feel comfortable and it gives the cervix time to close and reduce the risk of infection.