Lingering dizziness

We are trying to conceive could this be a sign of pregnancy? I woke up Sunday morning and tried to get up out of bed but I just felt everything around me move so fast that I just laid back down. I felt better a few hours later, but the dizziness has been lingering on and off since Sunday . I am supposed to start my period on the 28th so I'm eager to see if it comes. Today I was yawning all day long even though I feel like I got a good night sleep. Any thoughts?