scared! water breaking?

Tmi! I'm 21 weeks pregnant and I just got done having sex with my boyfriend (he finished inside of me) and I went to the bathroom to clean up. I put a panty liner on because I hate when his cum gets on my underwear. Anyways I went back in my room and sat on my bed and kinda laid back. As I started sitting up I felt this gush of something coming out of me (nothing like I've felt before) it almost felt like I peed myself. I went to the bathroom and saw what looked like cum and water mixed. I started having pains in my stomach but they went away and haven't returned. Was it just his cum coming out of me or something more. I'm kinda just freaking out and need someone to calm me down!