Am I pregnant?

My little one will be three months on the twenty third of this month. She was born February 23. The last day of my last period was April 4. I had sex about two weeks after that but I didn't let him finish because it was unprotected. I missed my period this month and I feel so sick, I could swear to you that I am actually pregnant. I took 3 pregnancy tests as soon as I missed my period and they all came out negative. I thought maybe it was too soon to tell anyway. I feel so nauseas and have period like cramps and I just feel like crap. Today I took another two tests and they came out negative. Where is my period. I feel that until I see blood then I am pregnant. This is driving me insane.