Nope, I wouldn't worry just yet (I know, easier said than done). I don't know where your chick from, but even hatchery quality Silkies are hard to sex. Breeder quality/show quality are even harder. One other thing to keep in mind, your chick looks like its non-bearded. Non-bearded females will have larger combs and wattles then bearded Silkies (some NB sport more head equipment then alot of bearded roosters).