Period Normal?

I’m 19years old. I had the implinan birth control in my arm for almost two years and got it taken out at the end of last year. Since then I have had a 7 day long period every 18 days instead of every 26 or so days. My periods always come with very painful cramps and about every other cycle I throw up all night long... Should I be worried or see a doctor? I’m also hoping this doesn’t mean I will have a hard time getting pregnant when I decide that’s what I want. I’m just wondering if my body is still trying to get back to normal even though it’s been over 8 months without the birth control. Any opinions? I appreciate it.