WHY IS MY PERIOD LATE 😫😫😫

Okay so my period is 4 days late. 😳 My bf and don't have sex very often the last we've been intimate was 3 weeks ago. We use condoms ALL THE TIME ! Before we have sex he inspects the condoms. My period was supposed to be here on the 16th of this month. I'm having semi-mild cramps. My breast feel heavy (which is normal ) but my nipples feel super sensitive and sore. Maybe I'm paranoid but my weight has been slowly going up within the last week. 😣😣😣 I'm freaking out. Idk what to do....is it too soon for a hpt ????