Ay oo, pwede na! Most of my mom friends started using pacifiers around 3-4 weeks, kaya 26 days is totally fine, just make sure lagi clean and sterilized. The 3-month indicator usually means the nipple size lang, so kung smooth siya and hindi too big sa mouth ng baby mo, gagamitin mo na yan without worry, pero if you're concerned about the fit, mas mabuti siguro to ask your pedia just to be sure since bawat baby is different talaga.