Missed Cycle

So my boyfriend and I have sex regularly. We always use contraceptives, but I don't take birth control because I am diabetic and the medicines contradict.

I am always very regular with my periods- every 29 days. Now, I have missed my period by three days.... And counting. And the strangest part is, the only symptom of PMS I am having is swollen and tender boobs. Other than that, slight mood swings.

I already bought a pregnancy test, which tested negative. When I told my boyfriend about it, he suggested I see a doctor and get blood work done. But I absolutely HATE doctors, and I don't want to be made a fool if there is nothing wrong with me.

What would you ladies do?