Anyone else experienced this? Could I be pregnant?

Yesterday morning I started what I thought was my period. I had sexual intercourse shortly after I started bleeding well more like spotting but there was a small clot on the toilet paper. My period was due in a 5 days. I put a tampon in took it out a couple hours later nothing on it at all. Later that afternoon I started spotting again put in another tampon took it out later still nothing. Haven’t bled since. My boobs are really sore but I’m super confused. Has this happened to anyone else and you wound up getting your period later?