Ay mama, nakakaworry talaga yan lalo na with everything you're going through sa hospital with your baby! Based on the timeline mo, March 9 is quite far from your fertility window (April 30-May 6), so pregnancy from that date would be unlikely, but honestly stress, puyat, and being sick can really mess with your cycle and delay it, happened to a few of my mum friends din during stressful periods. Since you're a week delayed na and gusto mo sure, the best thing is mag-take ng pregnancy test or check with your OB para malinis na, especially with lahat ng nangyari sa'yo recently (hospital stay, fever, diarrhea) kasi yan talaga ang common culprits ng hormonal imbalance. Praying your baby feels better soon, and you get answers soon too!