Im worried

Ive been feeling a little funny for the last past month. I keep getting headaches and feeling nauseous. Ive been getting my period on time and log as much as i can. I been feeling these moments in my stomach but my stomach is flat. Im a mother of a 1 year son and ive been feeling pregnant but test are negative and cycle been on time. My cramps has been worse then before i had my son. This morning me and my boyfriend was having sex and as we was moving from o e room to another i notice it was blood every where. I just got off my cycle a week ago so im confused. I went to the bathroom , im not sure if it was because i was drunk but i felt terrible all of sudden like i was going to faint. But the bleeding didn’t continue. What should i do?