My last period was on april 16th. My period was suppose to come on may 14th. Had surgery on may 7th took a urine test on may 18th and the pregnancy was negative. It is now 15days late. Why is it not coming

There are many reasons that we women skip a period. Pregnancy is only one of them.

Stress, weight loss, medication, weight gain, exercise, and so much more can effect your period.

You just had surgery. It's likely that this messed up your cycle.

There is still a chance that you're pregnant and it was just too early to test. Wait until your next period is due. If you skip that one then test again. Make sure to use first morning urine, and follow the directions on the test exactly. You could also go for a more reliable blood test at your doctors office, or planned parenthood.

Good luck.