Late period and brown discharge but no bfp. Am I pregnant?

[Emily_Ken]

I've been looking around at other peoples questions and I haven't got an answer that explains everything so here goes nothing... AF should have came on the 5th or 6th, but it didn't, however on the 2nd, I was ovulating (my friend studies midwifery so I know what fertile discharge looks like) so I assumed it would then be 17 days laterish I would come on like usual but nothing. Also, me and my fiancé are usually safe but on the 4th we weren't because I went away on holiday and forgot to take my pills. Now (26th) and nothing. However, I started having watery brown and pink discharge (usually only when I wipe) on the 18th for one day and then again on the 20th til the 26th with it getting darker for the 24th only. I have back pain but I assumed that was because we've got a new car and I'm not used to the seats. I've got itchy and tight feeling boobs. I've got a weird tingly feeling in my lower stomach and abdomen. I'm getting light cramps so I thought it was my body getting ready for AF. Im bloated and got sharp random mildish pains in my left side pelvis. I've had unusual wind and metallic tastes in my mouth. Also, I've been more tired. I put it all down to mother nature cleaning out and me being paranoid. I took a test on the 23rd and it was negative but I was discharging still. Today, its got very warm down there and slightly itchy (but I do shave and it gets itchy) I've also been getting bad headaches and hot flushes. It feels quite tight down there and my cervix feels quite low. I don't know if its pregnancy or just a weird cycle and I'm over reacting. Any ideas, it really feels like AF can appear any day. I was gonna wait for a week and take another test. Does anyone have any ideas or advice or think of if it could be implantion or something else?