+1 for the Weed n Feed, Lily Miller Ultragreen works well too if you cant find the Scotts or its sold out or whatever...

better to get rid of them now before its fully established, lawns full of weeds look like crap after you kill them off, and its not always as easy as just overseeding to get it back... kill em off now, reseed in 2 weeks, keep watering, and you will have a golf course by August....