Possibly Pregnant But Irregular Period

Fufu

Ok so May of 2018 I had my last birth control shot! Which means it wore off around the end of July early August. From August to November my period came on the 9th, then December I was 4 days late and my period started on the 13 and lasted 5 to 6 days. Now its January and my period is 5 days late again today is January 18 2019!!! Idk if I’m pregnant or what the hell is going on has anyone else experienced this??? I will take my first test at 11 days late.