Confused!!

[ScruffyPenguin]

I'm on the pill, but had unprotected sex 2 weeks ago while also taking anti biotics.
Since then I've been constantly nauseous, getting headaches, fatigued and light headed.
This is a bit random but I also tried dying my roots the other day (I'm blonde) and the hair dye just wouldn't take to my hair which is very unusual. My hairdresser said that can be a sign of pregnancy.
I've also had a brown discharge and a bit of cramping the last couple of days.
I took a test today and got a negative, but is there a chance I'm actually pregnant?
I'm supposed to be going on a night out on Saturday as well, and I'm really concerned about whether I should drink alcohol or not.
It's rare for me to go out and not drink so I don't want people questioning me as I'm not in a relationship.
I know this is a lot of information but if anyone can give any kind of insight it would be greatly appreciated

When was your last menstrual cycle? And when are you due again?

My last period was the 13th June. I was due again last week but when given antibiotics the doctor told me to keep taking the pill back to back and not have this period :/

Try not to worry. I know it's hard. Wait until you finish this cycle of pills and take your break, if your period comes then you'll know. Perhaps it's just the antibiotics, or it could be to do with running the pills back to back. The brown discharge and cramping could also be related to this. From what I know about pregnancy tests they can't give false negatives - so believe the stick. Enjoy your night out. If you're really really worried the doctor can do a blood test. Let me know what happens.

Thank you :)
I probably just needed to hear that off someone lol
Will keep the thread updated x