Could I be pregnant?

For the past week I have had real trouble peeing. I'll go and 5 mins later have to go again. I haven't drank enough to justify this and it is getting rather uncomfortable, feeling like I can't venture too far from the toilet. I also have very slight spotting and nausea. Myself and SO are in a LDR so don't have sex all that often and are usually rather good at using protection however once 2 weeks ago we forgot.