I started to pay close attention to BTC 3 weeks ago and its price was about $7000. And up to now its price was $12500, reaching it's peak. Is it appropriate to invest in bitcoins from now on？ 
I dont think appropriate is the best word to describe it but it is more of necessary because it is. If you invest at that time youve already doubled your earning for a month. So take a stronger stand if you really think it is worth to risk than be fear of losing in the end. It is on your own selfish decision and none will make change it but you.