Thank you very much for your question. It is our pleasure to answer it.

In the name of Allah, We praise Him, seek His help and ask for His forgiveness. Whoever Allah guides none can misguide, and whoever He allows to fall astray, none can guide them aright.

Dear sister, the blood that the you notice in days other than your normal menstruation period due to taking pills or other things is not considered menstruation blood. So, you should not, in this case, leave performing prayers or fasting or any other thing the menstruating woman leaves during her period.
We remind you, however, that taking contraception pills is not lawful except for a limited period and with the consent of the husband and provided that these pills do not have any negative effects on your health.

And Allah knows best.