It’s a mystery. And I desperately need help.

Okay. Let’s sum up this story to the short version. Me and my husband are parents to a 9 month old baby girl. I have been having a feeling I’m pregnant for over a month now. I’m nauseous, emotional and have been having horrible headaches. It feels like when I was pregnant with my daughter. But I’m still having periods and every week I take a pregnancy test just to make. Well lately I have been feeling movement in my lower stomach. I know I sound crazy, but I’m not. It’s little flutters and sometimes I feel kicks when I’m laying down flat. Idk what to do. I’m still have periods and all pregnancy test are negative. What is going on:(