Pregnancy right after first baby?

Okay so I had my daughter 8 weeks ago and did not get a period during that time. My significant other and I had unprotected sex about two weeks ago and the next day I took plan b just to be safe. A week later I began lightly spotting for a few days and had some mild cramping and now feel nauseous a week following that. I also am having aversions to things much like I did when I was pregnant the first time. I am wondering if I could possibly be pregnant and when I should take a test since I haven’t yet had a cycle? Any help would be much appreciated.