Feel like screaming!!! Frustrated!!!

Ok so basically since having sex last week (when ovulating) and unsure if we were safe using the withdrawal method I've been having sore breasts, tired, feeling sick, headaches etc and then last night (exactly 7 days since) I had slight spotting, so did a test today and got a negative, but now feel really irritated and snappy?! I don't know why?! Period not due until next week so bit early for pms?! Just fed up, am I pregnant? Had tummy bug? Or due on? 😢😔 hate the confusion of being female!!!