Welcome to the forum. The pink that you saw on the tissue is "spotting". Spotting can occur during implantation
), 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.