18dpo and Bfn

Renae • 💙 '09....💙 '11....💔 '14.... 💔 '14....💔 '15....💔 '16....💔 '17....💜 12/12/17
I'm 18DPO...and no sign of AF anywhere!!! My boobs hurt, I'm nauseous, have increased cm (which normally drys up b4 AF arrives). I'm sooo confused, I'm only ever 1-2days late....never longer unless I'm pregnant! I got a faint positive at 10dpo....now there negative....either give me a BFP or bring on AF!! I can get an appt with my dr until 25th march! Any1 got any advice to help me out??