So many questions....geographical location being a big one....which you might not want to answer.
What besides the two marks make you think it could be a snake bite?
Are you usually barefoot? Were you wearing shoes before? Sandals? Socks?
Where were you all day? In your yard, a park or out in the wilderness?
On the one hand that could be a bite from a small snake. But it could also be a spider. Black widows make two pierce marks as well.