Bottom wind onset at 3 months

[obsessed1]

My 14 week old baby is usually very happy and settled but in the last 2 weeks has become increasingly windy and distressed. She's exclusively breastfed. Now about 30 mins after every feed she is in distress, her tummy goes hard and she squirms around in pain. When she does manage to get them out, her pops are extremely smelly and there seems to be a lot of it for such a small person! Is it unusual to develop wind at this stage? I thought they were meant to grow out of it around now, not develop it!
I'm wondering if it could be a bug and whether the dr would be able to give her anything for it? I've read it could be linked to teething, which would make sense as she's showing other signs. Or whether it may be that she's developed an intolerance to my milk? She didn't have her 2nd lot of immunisations last Thursday, though her wind was progressively getting worse at least a week before that.
I've been using infacol but have just picked up gripe water to see if that might work better. I've tried baby massage, but doesn't seem to have helped much. Any other suggestions on how to help greatly appreciated! Or if your child suddenly developed similar problems around this stage... should I be worried, or just wait it out?

[obsessed1]

Sorry, that should read : 'she did have her 2nd injections', rather than 'didn't'!