af in a day and still no PMS???

so today is my cycle day 28 which I think im supposed to start my period today? or tmr maybe? but until now I still haven't had any PMS at all, just maybe realllly mild cramps that don't last all day like usual, they last like 10mins max. i had protected sex about 5 days before i ovulated and 9 days after i ovulated so i doubt i could've been pregnant but Im not ruling out the possibility. do you guys think im fine?..