what are the chances I could be pregnant?

So I'm super anxious, I'm really wanting to have a baby. I had my last period September 4th-8th. Me and my boyfriend had unprotected sex and he came inside me September 19th,20th, 30th and also October 2nd and today October 3rd. My periods a day late but I'm usually very irregular. I took a pregnancy test today, it said negative :( could it be too early to tell yet? I'm so anxious to know!! When should I test again?