can I be pregnant

Hey I've been feeling like I'm pregnant obviously..don't know if it's in my head or not. Lol. I've been crampy and boobs sore. My period wasn't like usual. I had it nov 19. Very light and little pain. I usually have intense the point I can't do anything and sometimes throw up. Well I didn't have that..can't remember the last time I had a period without intense pain. Also. I normally have a heavy flow for at least 4 days and the rest is light. I never had a heavy flow and only had to wear a tampon for 2 and half days. I have taken tests the past few days and they are all negative. Is it still possible to be pregnant??