38 weeks pregnant, slight bleeding?

So, I’ve been getting all the baby shower clothes/ clothes I’ve been given together and i lifted a bag that was filled with towels- it was a bit heavy, and i just continued on choosing baby clothes to wash.

Maybe 20 minutes later, i just peed and had some weird yellowy discharge and slight bloody tinted mucus. Is this normal? I Started to cramp up too. Should I call my obgyn? Or did i maybe just over do myself?