Early Pregnancy Bleeding

I'm currently 5 weeks almost 6 and yesterday started bleeding. Blood was pinkish red and enough to cover paper when wiping but required no pad. *tmi* when checking inside finger would be covered and dark red. This lasted less than 24 hrs before blood disappearing and CM returning to normal. Only cramping I had was related to constipation/gas and I always have slight lower back pain, even before becoming pregnant. Only one tiny clot passed, about the size of a tip of a pencil.

 Nurse said unless I start bleeding heavily or develop painful cramps to just keep an eye on it and relax. She thinks maybe it was from straining with the constipation/gas.