Getting periods again within 11 days suggests the cycle is not regular, which can affect ovulation and make it harder to conceive. The medicines she is taking are often used to support ovulation and hormones, but sometimes they may not work as expected, or the dose may need adjustment. It is important to track her cycle and ovulation timing, rather than relying only on medicines. She should follow up with her doctor so the cause of the short cycle can be checked and the treatment plan can be adjusted for better chances of pregnancy.