Help with conception!

Analise

So my boyfriend and I have been together for 2 years, and since the beginning we've never had "safe sex" about two months of being together, I got pregnant, we were not, by any means trying to conceive, but once we found out, we were actually very excited!! But just 2 short months later, I miscarried, and we were devastated, and ever since then we have been trying to get pregnant! After two years of trying, I've given up hope! I take pregnancy tests every month before my period, sometimes I feel like I see positive but then period comes a few days later.... can anyone give me tips and advice on how to help my body carry a pregnancy?