Eptopic or Not wonder how to figure this out?

I had my tubes tided back in 2009. Iv had 3 wonderful boys 11,7 and 2. I have always had a regular period even after the surgery to tie my tubes. Now Ive missed a period and am now 2 weeks late. I took a home test just to be sure. It was negitive and now Im having really bad pain in my stomach and side. I didnt have any spoting or cramps. I wonder If its a eptiopic or if the test would detect enough hormone level to read positve or not. I hate to be a worry wart and go to the dr if nothing is wrong. Any sudgestions on wether a test would pick up on HCG in a eptopic?