PMS or Early Pregnancy Symptoms

Update: Guess it's safe to say it was PMS. AF came a day early.

According to the app, my period should come on the 8th of this month. My periods have always been irregular, so I dont know when or even if I've ovulated. However, as of late my cycles have been around 35-37 days. About 2-3 days ago my nipples have been sore and I've been having slight pelvic pain. Today my gums seem a little sore. When my period starts I normally only have cramps that are not too bad. So could I be experiencing PMS or early pregnancy symptoms? When should I test?

When I conceived in August, I only had sore nipples that were not as painful as now and lower back pain. That pregnancy ended in a miscarriage.

P.s. I also use another app and enter the same info on them both but they are totally different. The other app predicts everything (ovulation, day period starts) like a week(give or take) earlier.