I am four days late for my period Yesterday I

Patient: I am four days late for my period. Yesterday I thought I started my period but it was very watery and light. Today it’s the same thing and I’ve got a bad pain in my lower stomach area. I took a pregnancy test a couple days ago and it said that it was negative. What do you think could be causing this?

Symptoms: Late period, watery bleeding, stomach pain, headaches, sleepy, dizziness, constantly urinating.