I am brewing my first batch of beer, using the Brewers Best American Amber recipe. According to this recipe, the Starting Gravity should be at 1.042-1.045 and the finishing should be around 1.021. My Starting Gravity is at 1.021. While boiling the ingredients, it did boil over once and almost did a few other times. After those events, it appeared the hops were left on the side. I did my best to scrape those hops back into solution. My question is what did I do wrong? And what, if any, effect will this low starting gravity have on the beer? Am I screwed?