unprotected sex after methotrexate for ectopic pregnancy

So about 3 weeks ago I got two shots of methotrexate for an ectopic pregnancy at about 6 weeks along and tonight my husband and I decided to have sex since my hcg is already back at 0 but we didn't use a condom. Is it possible that I'm already ovulating since it's been almost a month? I'm worried about ovulating and ending up with another miscarriage or ectopic pregnancy for having unprotected sex