period questions

So after I had sex I went to the restroom and thought I was going to start because I had cramps and when I wiped myself it was pinkish...well the next day was nothing I haven't started and that was 2 weeks ago. My period are irregular and I'm almost 2 weeks late last cycle I was 1 week late....I took a test and I'm not prego...what can be wrong with me ?😔