Help please. Need. Advice.

My. Next period. Isn’t due till 8th day 22cycle seven days past ovulation very very faint test yesterday had chemical at 4weeks 11th December cycle day 1 ended 13th December I passed embryo day 3 had sex days after. And right. Up till 26th what are my chances I tested at 2weeks 6days. Very very faint positive I was shocked I Could of caught early or late. Unsure 3rd January I’ll. be. 3weeks due date around around 18th September anyone in same situation as me please