My 3 months old baby is many times fussy at breasts.what may be the reasons? i m exclusively breastfeeding.?

i breastfeed my baby around 8 to 10 times in 24 hrs...

It might be foods you are eating that he doesn't like. Or maybe you need to increase your fluids.
Try to notice if some foods make him more fussy.
Also try holding him in different positions, some babies have preferences.

My daughter was exactly the same. She wouldnt settle down for a long feed very often, she would graze all day instead and quite often she would fuss when I was feeding her. I would just try her on the other breast as this sometimes worked or if not then I would lay down on my bed with her laying beside me to feed her as this relaxed her. She carried on like this until she was about 4 1/2 months old when I introduced a small meal of baby rice every evening. All of a sudden her habits changed and she got into a routine in the day of feeding every 3 hours (whereas it used to be about every 1 1/2 hours) and she now relaxes into her feeds and stays there for about 30-40 mins. I dont know why it made such a big difference, it must have just took the edge off her hunger and settled her a little. Maybe once your baby gets a little older and you can introduce some solids to his/her diet then the same may happen

Have a look at the foods your eating like coffee, chocolate, dairy can sometimes up set baby's or she/he may be not very hungry.