Isnt it too early to be experiencing pregnancy symptoms?

Im disgustingly regular on my period but now I'm 2 days late my boyfriend and I always use the withdrawal method any way I was told if he has previously ejaculated (which he had) that sperm cld be in the precum.. I'm 22 and in college not really ready to discuss this with my parents bc I knw they'll be disappointed but I've been feeling nauseous all thru out the day I've been getting dizzy a lot and I have no appetite my body feels tired and sore like I just wanna rest I feel like my legs are abt to give out sometimes but this incident happened almost 2 wks ago isn't that too early to be having symptoms of pregnancy?