to early ?

Vanessa
So far at a week and 5 days
 Is it to early to go for a blood test ? 
My period isn't due till the 2nd of may, 
my first symptom was my boobs hurting and my back then I got a sore throat, and runny nose and my heart is just out of no where beating really fast and yesterday I got a little bit of cramping in the morning and needing to go toilet a lot  not to mention over the weekend I was constantly over heating even when it wasn't hot