my DS was/is the same. He's 8mo now and still b on demans, and on average sleeps in 2/3 hr stretches throughout the night sometimes less. 14 weeks is still very young, and am sure that soon you'll start to all into a pattern.
I was like you and around 6/7 weeks I got into a right state thinking that I should be getting him into a routine as otherwise I'd be creating a rod for my own back by letting him eat and sleep when and where he wanted. In the end the only routine we've had is bathtime and bed time at around the same time each day, but sometimes its 6pm, other times 730pm, depends how the day has gone. Other than that I just make sure he naps when he's tired. I have to either take him or a walk in the pushchair, a drive in the car, or feed him to sleep if I put him in his cot.
Evern now that we're weaning there isn't a routine, more of a pattern where he has one meal each chunk of time he's awake - in the morning, ater his first nap and ater his second nap.
My friends ask me how many bfeeds a day he has each day, or when his next feed will be, and I just always vaguely reply, "oooh, who knows..each day is different".
You're doing great. If your baby is thriving then you're clearly doing something right, and do what works or you. A happy mum means a happy baby.
Having said that, in evolutionary terms your baby needs you to survive. If in order to survive you need to get him onto a more predictable routine then he will allow himself to be tweaked and manipulated into a routine. I don't necessarily think a baby does better on a routine, its just that some mums do better on a routine, and if the mum is doing better, so is the baby!