insanely sore boobs

Hi ladies I've had extremely sore and engorged boobs for about four days now and I can't figure out why. They feel horrible and extremely huge, about a 34F. This only happens when it's  1-3 days before my period, but my period is in a week from now. My periods are usually very regular; sometimes only 2 or 3 days off from each date. Is this a sign for anything? I do have unprotected sex regularly using the pull out method, but not TTC! Thank you all :)