Spotting

So I’ve been on the pill since I was 18, I’m now 25. In all the time I’ve been taking the pill, I’ve never experienced spotting. I haven’t had a period since the end of March as I’ve taken my pill continuously without a break. All of last week I was spotting when I wiped and it was a pink/red colour. I’ve also had really mild cramps and today I bled after sex for the first time. I did a pregnancy test on Wednesday to put my mind at ease and it was negative. Is this something to be worried about? Anyone else had similar experiences? 😢