Ay sis, based sa experience ko at ng mga kaibigan ko, ang pinakamabilis na sign talaga ay ang delayed period, that's usually the first clue na something's different! Then comes the crazy pagod, parang walang tulog ka pero gutom ka pa rin, at yung boobs mo parang mas masakit at nag-swell, kaya uncomfortable mag-bra. A few of us noticed din na sudden yung sensitivity sa amoy, parang ang lasa ng favorite food mo biglang nakakainis, or kumakati sa ilong mo ang mga bagay na okay lang before, haha. Some of my mum friends also felt slight cramping and spotting early on, pero mas malalaki yung chance na it's really buntis kung marami nang signs combined, so better to take a PT just to be sure!