i need to know if im pregnant??

%-) hi im liza and i need to know if im pregnant? my story would be that i did it with my boyfriend about five times and he came in me in all and i get some of the symptoms and i get cramps in my part. and i get my period but not regular and lighter. my breast are tender and heavier and there growing. and i get mad really easier and i lost weight, i dont eat like i use to. so later that time i took two pregnancy test they came out negative. so i thought i wasn't, so then we still do it but ever since that time when we do it it hurts like if it was my first time and then we dont last long cause he hits me with his thing somewhere in my belly and it hurts. well we still do it and i never come out pregnant i check myself but now they come out invalid result i would really appreciate if you help me cause i really need your help?? PLEASE HELP ME??