Symptoms of HCG elevating after 3 weeks a post d&c

I am really confused and worried and anxious waiting on my period. Me & bf had sex a week after d&c everything went well and stopped bleeding shortly after the d&c maybe 3 days max & for two days it was just very light and spotting until it disappeared. Now it has been 3 weeks exactly since I had sex with my bf, I took a hpt and was negative although this morning I woke up with tender breasts and nausea and vomiting. Exact same symptoms I had when I found out I was pregnant, I want to be pregnant but at the same time I don't. Any advice or experience would be helpful, tyia!