Hello, Welcome to the forum. The pink that you saw on the tissue is spotting . Spotting can occur during implantation (pregnancy), if you have been sexually active. The other causes can be ovulation ( some people get mid-cycle spottting on ovulation), spotting can be due to intake of birth control pills ( missing pills ). It can occur in Polycystic ovarian disease (PCOD) or Pelvic inflammatory disease (PID). Other causes can be low thyroid levels or hormonal dysfunctions. You should consult a gynecologist, get clinically assessed at the earliest. You need to get few investigations ( blood and urine ) done. Get diagnosed and treated. Take some antioxidant and mineral supplements, keep well hydrated to get rid of tiredness. You can take some antacid medicine to feel better. ( consult doctor before taking medicines and do not take over-doses) Have a good day, take care.