Imdavies,
Although you showed early signs of male pattern baldness at the young age of 18, now you're 30 and it may very well be the meds you are using right now that is slowing the effects of male pattern baldness. None of the meds will completely halt the progression opf male pattern baldness, only slow it down. And we know that there is no cure for male pattern baldness as well.
The family history perspective does not attempt to precisely predict when genetic hairloss will begin, but rather the "potential extent" of loss. The doctors know that male pattern baldness is progressive so if there are more advanced classes in uncles, grandfathers, etc, they have to consider that there is a "possibility" that it could happen to you. They want to be sure and YOU want to be sure that you have some donor left for future loss. And family history does take into account both sides, maternal and paternal. In my own case my paternal (father) side has no male pattern baldness history. But my maternal (mother) side is where I inherited male pattern baldness. It also hit my mother who experience extensive hairloss and my maternal grandfather eventually reached Norwood class 6 by the time of his passing. According to my mother his hairloss became more advanced when he hit his mid-to-late thirties.
So really the bottom line is that you want to plan your surgical hair restoration with considerations over a lifetime, always prepared for the worst case scenario. So the more potential for advanced male pattern baldness, the more conservative hairlines and density would be.