That sounds reasonable. It can be given from 2 months without prescription, but could potentially be given to younger ones when needed if a doctor has prescribed it. I think the calpol instructions say 2.5ml twice a day (but I could be wrong). However, an 11 week old baby is bigger than an 8 week old baby and I think by 3 months they can have it 4 times a day. As the doc has seen your LO, I would stick with what they recommend.