Menstrual irregularities are quite common for a number of different reasons. The entire menstrual cycle is dependent on a number of different hormones that can be affected by a number of different factors. Your overall health, stress level, and nutritional status will play a role in this as well. Most important to answering your question is determining what is normal to you. If your period has changed in the recent past, this is likely a sign that you need to speak with a doctor
sooner rather than later. If these changes you describe are chronic in nature, then it is more likely something to do with how your body responds to the cyclic changes than something new. Either way, you need to speak with your doctor. Longer than normal menstrual bleeding
can be a sign of many things, including thin blood (for example, if you are on aspirin or take any other blood thinners or have a genetic predisposition to easy bleeding or bruising). Also, it could be due to your oral contraceptive if you are using one or have changed this recently, as they do take some time to normalize. Again, please speak with your doctor about this question.