wtf is this?

Brittany • 20. Married to my best friend. Puppy enthusiast.
So I believe this is normal but I just want to make sure. My fiancé and I had sex for the first time last night, while my period was just starting(superlight spotting). I have been on the pill, so we had unprotected sex and he did not finish inside of me. I have never had this thick, or elastic type of discharge before. It is completely clear and super stretchy. Any ideas? Thanks in advanced, ladies! ❤