I had sexual intercourse and the next day I got my period 12days later I spotted light pink blood that only lasted 1 day can that mean I'm pregnant?

Unlikely, but test! Pregnancy tests, even over-the-counter ones, are very accurate. Generally, if you conceived more than 14 days ago, the pregnancy test will be positive. There is a chance that you conceived too recently for the test to pick up the low levels of hormone in your system. If you had intercourse less than two weeks ago, then you will need to repeat the test when it has been at least two weeks.