There has been a little drop of semen on my underwear, but she didn't see anything on hers

I WANNA ASK SOMETHING​​ 

I was playing with my girlfriend in our underwears and with my underwear on..I tried put my penis in her vagina even though she was also wearing her underwear ..and after..I saw a little drop of semen of my underwear but she didn't see anything on hers....I am so nervous and I want to ask whether she'll get pregnant or not