Liquid coming out after 3 days past when I was supposed to start my period?

Jayden • 18 year old who wants to mother our first child and many more to come. ❤️

I'm on my third day that I was supposed to start my period. I got out of bed and me and my boyfriend noticed there was this small puddle of wetness that was clear. We aren't sure what it is. I took a pregnancy test about 4 days ago and it had a faint line but I took one the morning after and it said negative? So what liquid is this?