Implantation bleeding for 4 days?

Has anyone had implantation bleeding that lasted 3 to 4 days? I just assumed I was getting my period but it was much lighter than normal and there was barely anything by day 4. I never have a period last less than 7 days. And since then I've had a few pregnancy symptoms but it could just be in my head lol. I don't want to test until I'm a little more convinced because I hate getting a negative test! :-/.