Period but feel pregnant?

My period was a week late this month.(usually regular). I took a test 2-3 days when I was late and came out negative. I bled on June 1st(no period in may) it lasted for about 3-4 days on and off. 2 weeks later and I have a lot of pressure in my right lower abdomen area and pain in my lower back,pain under my armpit, heartburn in the mornings. Has anybody ever experienced this and still been pregnant? I have an appointment on Monday but just want your opinion!