Is it normal to have symptoms this early?

My boyfriend and I had sex (unprotected) on the 5th, 7th, 8th, 11th,12th, and again today (13th).Since the 11th I have been so tired. Some days I can't make it out of the bed till 10. I also have been feeling nausea and cramping, and today it's worse. Today, my breast have been kind sore, and I had a bad dizzy spill, with a headache. I don't know when I ovulate, but I do know my period was around the 22th of July. I have also had a little spotting, but it was so little. We are trying to have a baby, but I want to know is this normal, could I be pregnant?

Extra info:
I normally don't cramp till a few day before my period.
My breast normally don't get sore.
I only get dizzy when I stand up way to fast, and never fallowed by a headache
I am very good about getting out of bed early in the morning, and not wanting to sleep all day.

Please someone help me. Thank you. =)