Is it normal: to want to have sex with pregnant girls?

Ok, so im in this drug treatment class, and there is this really pretty girl. At first i wasnt really interested in her, then i found out she is pregnant. Its been a few months an her belly is just starting to show, and it really turns me on. I wanted to know if i was actually got horny over pregnant chicks so i googled them. I found out that the farther along they are(the bigger the belly) the more turned on i would become. The best part is, i think she is interested in me. I really would live to have sex with her once she is farther along. Should i go for it? And, is this normal?