Spotting or implantation bleeding

Alex
So I never spot but for some reason I have been and it is making me worry that something is wrong. I had sex on the 13th without a condom but I am on the pill and take it at the same time every night he also pulls out. Sex kind of hurt because I don't think I was wet enough and the next day I bled a little. We had sex again on the 15th and I was fine. I had spotting on the 18th which is 5 days later so I was worried that it was implantation bleeding but I figured it was too early. I am having spotting again today and my period is supposed to start in two days. Do you think I should be worried? I also went on a bike ride today so that could be contributing to the spotting.