Symptoms seem to indicate pregnancy?

So I was home alone last week and my boyfriend decided to come round, we were fooling around and I ended up wanking him off and he fingered me, we didn't go as far as sex but I'm worried some of his semen still managed to enter my vagina as we were very lose and today I have felt sick all day and threw up in my mouth yesterday, and I haven't been sick in years. I'm feeling nausea, slightly bloated, dizzyness every now and again, also some back pain and headaches, but I constantly get headaches anyway. It is possible we have had close contact before last week but this is the first week of my symptoms, help and advice would be very appriciated. Thankyou x

I have reposted this again as i need more help and advice as soon as i can get it, possibly from someone who has experienced this before or could help me diagnose my symptoms as something other than pregnancy, i understand my symtopms are brief and i will be happy to explain more in detail about symptoms and anything else such as when my period is due if it would help; Many thanks in advance.