When you are having recent irregular periods
which were regular in the past, you may think of two things- a pregnancy
or a hormonal imbalance. As you had a negative urine pregnancy test, you may get a blood test
followed by a trans-vaginal/pelvic sonogram which can be confirmatory. Weight disturbances, polycystic ovaries
, thyroid disorders, infections, drug interactions and stress are some of the reasons that could cause irregular periods. The symptoms you have are not typical of pregnancy. I suggest that you see your gynecologist for a complete assessment and management. Take care.