I had surgical abortion 19 days ago. went on bc after abortion. had brown blood for a week and stopped, now started to have red/pink light bleeding?

Sounds normal: Spotting and light bleeding on and off for a few weeks after that procedure is expected. Usually i schedule a 2 week post op check and evaluate my patients for "retained products" or infection. If you haven't had that appointment, i would recommend scheduling it. But most likely, you are just healing and getting used to the pill all at the same time.