Hey that's good! Better than when i first started anyways
You should be able to create an ok alien in 2 weeks. For something like the alien that I linked to, it will take a bit longer..
You might want to check out MakeHuman:
If you set some extremer parameters than for a normal human, you should be able to get an alien quickly and easily. Unless ofcourse you already have in mind what it is supposed to look like. If that's the case it really helps to draw it out first and then model from that.