Low white blood count is a early indecator of over training it may only be over reaching.
You need to have 3 days full rest before having blood tests the reason is when you do big training rides you empty the glycogen tanks. so naturaly the blood is full of water and carbohydrate. If you waigh your self day after a long hard ride you will usualy be up to 2 KG heavier. extra water . if you have one of the computer balance scales you will note weter ballance up.
Low white blood Low sodium . High fasting glucose Low testosterone
high systoloic blood presure.
That is just enough for the Doctor to put on a whole dose of pills to slow you down.
There is nothing in low white blood count to worry about a couple of days rest and its ok.
high white blood count is bad news but you would know about it you would probably have a virus.