Am I pregnant?

I don't know if this allowed, but I am 7 days late on my period today. I took a pregnancy test on the 21st but it was negitative. Was it too early? I had sex on the 7th, 8th, 10th, 12th, 14th, 19th and 27th of this month. Could I be pregnant? We don't use protection. I was supossed to start on the 22nd.