This cycle or last?

I decided to take a test today, just a random feeling.. took about 1min for a faint line to show. took with (fmu) then with same urine tested with FRER and got a faint within 2 min... drank bottle of water, tested twice again an hour later and 2 negatives(diluted obviously) then another tonight after 2 hour hold & was positive again. I remember my period in july being very faint, but on time, and kind of short. Had EWCM on july 23rd & also BD. Did I conceive this cycle or last??? I feel like 15dpo is too soon to get a line this dark.