Won't nurse during the day...

So my daughter is 2 months old. For almost a month now she refuses to nurse during the day. She will when she wakes up and maybe once if she's really sleepy and takes a nap but other than that everytime I try she just screams and is so mad. Ive tried different positions and nothing works. But she nurses just fine from bedtime until morning. I pump every 3 hours throughout the day so she can have a bottle but she was doing this before I gave her a bottle, that was one reason I did. I just dont understand it :(