My (26M) girlfriend (30F) got pregnant by somebody else

My (26M) girlfriend (30) got pregnant once we had a small separation and I thought it was line

I’ve been trying to grieve but will admit I’ve been going through it really bad especially today.

We were together for about 2 years and lived together then she randomly wanted to move out in November last year to try to get her own spot for the first time in her life. Overall, we had amazing communication, chemistry and she was honestly my bestfriend but she struggled financially and i felt the age gap kind of got to her. Either way, in January, im basically telling her how I want to marry her and she seems ecstatic about everything. We even go on a elaborate nice date on Valentines Day. We ended up having sex that night but I didnt think about it. Two months after, she tells me shes pregnant and that its probably not mine since she had a drunk hookup. (i pulled out as well)

Obviously, i was so hurt so i stopped talking to her for two weeks. The whole time we were talking about marriage and love so this just shocked me. We ended up talking again few weeks later and it felt good, her mom has a feeling we should do a prenatal paternity test. It actually comes back positive that im the father. I tell my family and their so excited. But then that same evening, i checked reddit/google and their were some sketchy pieces. We ended up doing a second test that’s significantly more accurate and it comes back today that its negative. Im not the father.

I want to move on but im so hurt from everything being dragged on and being lied to so much. Why are people like this? Is there anything left for me to do in this situation? Shes religious so probably no abortion.