You should definitely be seeing small carrots by now, what soil did you plant in?

I dug my veg patch 3 metres by 1metre , put six inch timber frame round, then used five bags of peat free compost, 4 bags of sharp sand, 2 bags of topsoil, dug it in ,mixed it well and left it for a fortnight, hoeing daily. It looked and felt great, planted all my seeds and waited. Was rewarded quite soon with seedlings off all the varieties, so was optimistic.

It is possible the soil was too rich for carrots, they prefer a very lean sandy soil, that said we've had problems with carrots not doing well this year.