I am taking a continuous contraceptive pill (Marvelon/Mivala), but I still have my period. Could it be that it's not strong enough?

It is possible that you are experiencing spotting or bleeding while taking the pill continuously. This is a common side effect and doesn't necessarily mean that your pill is not strong enough. Some women may not be able to take the pill continuously for a long period due to this reason. If you are considering changing your pill for this reason, you can speak to your pharmacist who can consult with your doctor. A different pill may have a higher dose of estrogen or a different progestin which could potentially help with the issue. However, changing pills does not guarantee that you won't experience the same problem. It is often recommended to continue taking the same pill for as long as possible in a continuous manner, and to take a break for 4-5 days when bleeding occurs. This can help reduce the duration of bleeding if you need to take a break every 2-3 months.