Help please !!

Idk how to explain it but my nipples have felt weird for about 5 days. Like when I’m getting out of the shower and drying off when the towel touches my nipples they’re sensitive. Also ive been having like a throbbing sensation in my boobs.. My period is due in 4 days but I’m getting bfn. Is it most likely just af symptoms? I usually don’t have prolonged symptoms before my period