TTC for 3 years now! Advice needed

I'm wondering if anyone has had any success with getting pregnant with any kind of vitamins or supplements? My OBGYN said that my blood work is fine and I'm very regular, except my testosterone levels are a little high, so he doesn't want to put me on any prescriptions. We conceived my son without trying, but now the second baby doesn't seem to happen. Does anyone have any positive suggestions to try?