The Munich will affect the color, taste, and gravity. If you like a little malt backbone in your IPA you should probably get more Munich. If you like dry hoppy IPAs then skip it. If it were me I'd probably get more and then check my pre-boil gravity and adjust my hops if necessary. That way even if you add twice the Munich you can add more hops and the beer will still come out balanced and just a little higher in alcohol. Likewise though, if you skip it you can always back the hops off a little if the boil gravity comes in a little low.
If the wort is yellow you forgot the Munich. If it's orangish you added it. Good luck.