Symptoms?

S
Hi ladies. My husband and I had intercourse on the 20th of this month. Yesterday and today I can not shake the constant nausea I feel, the pressure in my lower abdomen and the headache. To top it all off, I locked myself out of my car and house TWICE today. This short term memory thing never happened to me. Oh and I've had very serious vivid dreams. 
I am not even sure if I ovulated(most likely did not as it was the day after my period ended) that night. 
I am trying to talk myself out of thinking that I am pregnant, but I have never been this nausceous.
Girls, talk some sense into me. I have been in bedxallxday today and yesterday because of my nausea. 
Did any of you experience anything like this within days of possible conception?