2weeks late having cramps and my boobs hurt?

Hello,
Welcome to the ehealthforum and I am really glad to help you out. Missed periods is one of the earliest symptoms of pregnancy but since you have got a negative urine for pregnancy test, I would suggest you to get a serum HCG test which is more sensitive than a urine for pregnancy test.

If it comes negative, then I’ll suggest you to consult a gynecologist and get evaluated for the various possibilities of missed periods like hormonal imbalance, increased stress, eating disorder, increased smoking,alcohol or caffeine use or medical causes like PCOS, fibroid, polyps and endometriosis.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.