Is it possible to get pregnant 4 days before real period starts? Came off nuvaring in january and had a real period last month feb. 18th.

Maybe. Most women are most fertile around day #14 of their cycle (counting the first day of your period as day#1). 4 days before your period is probably a time that you are much less likely to get pregnant, but it is risky to just guess, especially if you are trying not to get pregnant.