Got my period late last month but early this month?

so I usually get my period like the 5th and last month I got it the 22nd.. I haven't had sex in months and its always come between the 5th-7th. I figured it was was going to be late a few days because February was a shorter month but it was 2 weeks late. then right now I was just watching tv, eating then I started getting cramps and I thought because I had to pee for awhile but held it in but when I wiped I got a little scared haha because turns out I got my period. so im assuming its early because I thought I had like another week to go. I thought it was going to be on the 22nd or something. I haven;t even been stressing either. well a little, i've been focused on figuring out what makes me happy in life and not so much in school, its my second semester in college and got Cs last semester so if I get another C this semester I won't be able to transfer to the UC I want to go to. but I mean, i've stressed a lot more other times. I don't know whats happening ughhhh I dont even have insurance right now so I can't go to the doctor. I know freaking out about it also doesn't help so when I found out my period wasn't coming last month I just ignored it bc I knew I wasn't prego or anything. what could this be -_-*
I haven't changed my diet much either.
Got my period late last month but early this month?
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