What is going on?!

Okay so my period was due on the 13th and every month I’m right on schedule. I’m never late, I’ve been cramping these past days for only like 30 min and then completely go away. I usually end up getting my period right when those cramps start but I haven’t. Last night I got a lot of watery discharge with a little streak of blood but that was it, I definitely thought I was gonna get my period but she’s a no show! I took a pregnancy test this morning but BFN 😔 has this happened to anyone and later on gotten a BFP?!