A day before father's day,my boyfriend and I had intercourse

Question:
A day before father's day,my boyfriend and I had intercourse without protection just for two minutes or four . maybe less. Two days later I was bleeding for a while but it went away. the second to last week of the month of June, I was excepting my period but all I had was Brown discharge that went from Brown ,reddish to black to bright red. The bleeding occur on June 29 but my period wasn't suppose to be bring red and it lasted for nine days. yet my period supposed to last for four to seven days And heavy. my period is irregular so it harder to keep track. The symptoms I have been experiencing is stomach pain that started from the left to and move to the right of my belly button, breast swelling to and at times they feel more tender and squishy , sometimes nausea, fatigue, and maybe bloating and decrease appetite . Today (July 28)I feel I may have my period but I feel the same bleeding, bright red but severe cramping like a period and the flow is different . on the first The June 29 bleeding I told a pregnancy text and it was negative (3 tests) . my friend say it might be because of stress.Also today (aug.1) im experience brown blood and im wondering if i could be pregnant.