Hi! Okay so based on what you shared, there's definitely a chance kasi depending sa cycle mo, that third day after your period started could fall within your fertile window, lalo na kung ang cycle mo ay mas maikli, around 21-24 days lang. A few of us mums talk about this sa group namin at honestly, the safest route would be to take a pregnancy test in about 2 weeks or so, or better yet, check with your OB para malaman mo exactly kung kailan ang ovulation mo at kung safe kayo or if kailangan ng family planning. Hoping for clarity for you, sis!