For the past few months, my period has come on time, but it's been short and light. I've been nauseous and have gained weight recently (about 10 lbs, I think it is from not exercising and overeating though). The last time I had sex was 5 months ago and that was without ejaculation. I've been on the pill for about 8 months. Since I've started the pill, my period has been regular and lighter but the past few months have been especially light and I'm worried I could be pregnant. I know you can have spotting that looks like a period in early months of pregnancy, but I've been having light periods for a while so maybe my period has just changed. Should I get a pregnancy test or am I just freaking out?

Just to be clear I have had a period at the right time every month since I last had sex

The main thing I'm concerned about is the nausea because it's often and I've never really had that before. But I guess that could also be stress/anxiety