Husband on Testosterone Therapy

My husband already had low sperm count we aren’t trying for a baby so we decided to put him on testosterone therapy to help in ED. Well the Dr told us it like male birth control so we had unprotected sex for the first time sense I had our kids on days that I was so sure I wasn’t ovulating because my period was due to start any day. Well now I’m 10 days late and I’m wondering if it’s possible to get pregnant on testosterone therapy?