I thought I was pregnant and I was showing most symptoms. I'm 4 days late on my period and I had some blood today and so much pain in my lower abdomen?

Take test to confirm. When your menstrual cycle is late and you experience symptoms consistent with pregnancy, you should try to confirm your pregnancy status asap. This is important because it allows you to get early care which is important for you and baby. Pain and bleeding in pregnancy can be a sign of problems. Also, you can have missed cycles for reasons other than pregnancy. Your doctor can help sort things out.
Answered already. Please see my answer from earlier today. You should go to the emergency department.