Called in sick for the first time. Whatever I had yesterday got worse on my flight back. Head stopped up. I was assigned a 4AM-7PM RAP. They tried calling me at 10:30PM last night. I didn't answer the phone. I checked open flights. The same turn I did the last two days was open. Total of 6 hours of flying. When they called at 4:30AM I advised I was sick. Now on Sudafed-D. Time to rest.