Tired all the time ?

I will be 24 weeks on Tuesday ; I go to college classes Monday / Wednesday , i Work thursday - sunday.. Applied for a new job longer hours more money means I can buy an apartment & provide for my baby boy . Is it normal to be exsausted?? I can take a nap and sleep for 3 hours and wake up with the worst migraine, but have to get ready for work or study time .. Any tips on time management or being a better mom?