What's going on with me!?

Hi! So I woke up this morning went pee and I saw blood that was reddish and pinkish color on the toilet paper I was confuse because I had a period this month on the 3rd ended the 7th, so I put a tampon in and took it out at the correct time you take tampons out and it was brown? Like the color you have when you end your period.... I'm having cramps but not at painful but I know they're there!

I'm very worried on what's going on with my body..... I did have sex last night with my boyfriend though thought I'd throw that out there.