Has anyone ever got a faint positive on a Walmart test 6-7dpo?

Beth • Newlywed with 7 and 2 year old girls .. trying for #3
Ummm.. Should my HCG be this high at 6-7dpo? Had a positive O test one week ago today... I know it's thin but it popped up in 3 mins and I got a faint positive on an FRER..