one day period?

me and my boyfriend have been dating for about a month now and we didn’t use a condom the second time which was about 2/3 weeks ago already. my period was supposed to come on the 17th and it lasts for a full 5 days, but it came the first day, was pretty light, maybe filled up a tampon and left that same night, and now it being the 26th, my body has really went downhill, from being active to becoming exhausted without doing much, cramps with no period, tender tits, my body, head and lower back ache more then half of the day and usually i’m always covering myself up even in summer but i’ve been feeling like my temp has been hotter then usual. Is there by chance i’m just getting my period late and that’s why i have these symptoms? or could i possibly be experiencing early pregnancy signs?