Preg? I have a 6mth old. Help!!

My husband and I were going to start actively TTC in a few months, maybe a little after the beginning of next year. We got a little carried away with the BD in the heat of the moment on a night that happened to be in my fertile window for the first time since my son was born in April of this year. I’m 1DPO and I just need to know if I’m crazy or if I need to start testing in a few days. Definitely earlier than we planned but welcome none the less if this turns out to be real! Advice? I’m scared 😬