Low milk supply

I was facing low milk supply and supplementing my baby on formula. She is ,5 weeks old. I have been trying many things to increase my supply. I feel the change with my breasts feeling full every 2-3 hours comparee to earlier, But I am confused if I am able to keep up. . While feeding, I am.constantly worried if she is getting milk or she is just suckling.

Sometimes she keeps sucking for more than an hour, is that ok and does that mean she is getting milk for that long.

Sometimes she shows signs of hunger after my feed Specially during evenings and sometimes she is ok.

Also, she is having more than 15 wet nappies. Does that mean she is overfed?