I had a regular period in march then two weeks later i had a 3day period. the day after i had unprotected sex and i'm not on birth control. is it possible to be pregnant? when should i test?

When to test: You should do a home pregnancy test if you are more than 4-5 days late on your next expected period based on the normal one that you had in march.

It's possible: It is common for women's cycles to vary depending on their stress, diet, genetic factors, and hormone levels. If your regular periods last from 5-7 days and you've only had one unusually short menstrual cycle, i can't answer what the "new normal" is for you until more time has passed. You can take a pregnancy test now, but then also in another couple of weeks. (basically 6-8 weeks after sex).