My period usually comes on the 23 of every month. Buth for march it came on the 19th to the 23th a couple days early but normal. Now late on the 24th my back was hurting real bad. The morning of the 25th still in pain I went to the restroom and wipe it was blood now is this normal. Last month had unprotected sex on feb 16. Should I be worried or is this normal.

The problem with this is that, you're talking a couple days... Days aren't really that big of a deal. Plus most periods last more than one day, they're usually like 5-7 days.. It doesn't really seem like a big deal, but if you have to question it then I would suggest getting checked. If you really think there might be a problem then maybe there is. You should get checked for STD's and STI's after you have unprotected sex anyway. It's a dangerous game to play now-a-days. Most things are treatable in some way, but it's important to get checked as soon as you think there is a problem, otherwise it could cause future problems, and you don't want that. Back pains during menstruation are normal, but there are some infections that include back pains too. I'm sure it's no big deal, sounds mostly like menstruation, but never a bad thing to get checked and be sure! =)