Possible pregnant??????? help plz?

Okay so i had my period about march 27 and got off about april 3rd or 4th, i should of started the end of april and i have not yet but on the 29th i felt like i was bleeding but when i wiped i wasnt so i waded toilet paper and put up me and took it right out and there was pink so i put a tampon in cause i thought i was starting and about 4 to 6hrs later there was no blood or anything on the tampon. Today may1st i still havent started could i be pregnant? My nipples are sore when i rub them or squeeze them lightly. I do have irregular periods. Slight cramping but not badd, constant, or alot just seldomly