Hello i have never had any problems after sex until my latest partner. When we have unprotected sex, within a few hours I feel nausea and cramping in my lower region, and sometimes throbbing of my genitals. And this lasts for about 2 days. I am fine when we use condoms. Could I be allergic to his sperm? Or could he have an std? I have been checked 3 times now and its driving me crazy not knowing whats wrong with me..