According to Healthline, below are the effects of birth control pills.
1. Intermenstrual spotting
Approximately 50% of people using the pill experience vaginal bleeding between expected periods – also known as breakthrough bleeding – most commonly within the first 3 months of starting to take the pill. Generally, this resolves in over 90% of cases by the third pill pack. During spotting, the pill is still effective as long as it has been taken correctly and no doses were missed. People who experience 5 or more days of bleeding while on active pills or heavy bleeding for 3 or more days should contact a healthcare professional for advice.……CONTINUE READING
2. Breast tenderness
Birth control pills may cause breast enlargement or tenderness. This side effect tends to improve a few weeks after starting the pill, but anyone who finds a lump in the breast or who has persistent pain tenderness or severe breast pain should seek medical help.
Reducing caffeine and salt intake can decrease breast tenderness, as can wearing a supportive bra.
3. Missed periods
There are times when, despite proper pill use, a period may be skipped or missed. Several factors can influence this, such as stress, illness, travel, and hormonal or thyroid abnormalities. If a period is missed or is very light while on the pill, a pregnancy test is recommended before taking the next pack of pills; if further periods are missed or are very light, seek medical advice
