Trying to conceive with my second.

My first is a girl she’s 16 months old.

We’ve been trying for about 5 months now.

I haven’t had a period for 4 months. I’ve had spotting but no actual period.

I’ve at home tested at least 3 dozen times and had blood test and urine test done at obgyn. Had 1 positive at hone test and then All negatives. BUT I’ve gained weight like crazy. I have an almost pudgy round belly like I did when I was about 17 weeks pregnant with my first. And now I’m feeling almost flutters in my belly. Idk what to do or what else can be done in my situation. Any advice or tips would be helpful.