Cluster feeding or human pacifier?

Nabiha

My baby can be on and off the boob and fuss and scream cry multiple times of the day. When she does get on she doesn't feed as though she is ravenous and just nibbles at the boob a bit. Then comes off and then cries and the cycle continues. Is she either

1 not getting enough milk and getting frustrated

2 using me as a pacifier

3 cluster feeding