Am I pregnant or crazy or both?!

Bon
Ok so first off I am an adult in a long term relationship and I don't take any contraception. 
Ok so my boyfriend and I were doing the deed 💦 during my ovulation without any protection  (I clocked that it was my ovulation after I added the dates up) and the day after (Monday 14th) I had some slight reddish discharge like bleeding and it didn't last very long at all. I ignored that and put it down to rough sex. 
 
That week I had a few symptoms I didn't really put together but put them down to stress. Such as, major fatigue, painful breasts and back, peeing all the time, metallic taste in my mouth, and hungry. 
I've done 3 pregnancy tests in the past 2 weeks and they were all negative . I am now 6 days late for my period and I have a doctors appointment in 2 days. 
I'm more tired than usual other than that I can't notice maybe symptoms. Except constant nausea and a lot of pain in my boobs but again I thought that could be stress. 
I might add that my period is usually regular! Give or take a day or two, so I'm trying to figure out whether I could be pregnant or if my body and mind are just playing tricks on me. Anyone been in the same situation? Could I be pregnant ? Is it too soon to tell?