I honestly dont know whats happening.

So me and my boyfriend had sex maybe 3 weeks ago with no condom and im not on birth control, but he did pull out. My period usually lasts a week and a half, at the least a week..usually very heavy and pretty serious cramps. My last period was last week it lasted 3 days with terrible cramps, i had to call off work. And it seemed like a regular period until i stopped bleeding. Ive never had a period last anything less than 5 days but like i said its been a week to a week and a half since last year. Now i am having terrible stomach pains, some weird discharge, gas, and diarrhea. Some nausea but no puking. I haven’t taken any tests cause a lot of times i take them and they are negative so i waste money. So idk if im overthinking or if its possible im pregnant. Advice ladies?