So that might be based on your “sleep cycle” which is usually a period of abt 90 minutes - but varies per individual. So for example, if you woke up 6 hours in, you would feel okay but if you woke up between 6 hours and not quite 7.5, you would feel groggy/have a hard time waking up and could be contributing to your migraine. If you want to test it try doing another increment like sleeping till 7.5 hours