Wash baby clothes but what if I need to return?

So obviously I have an abundance of clothes some iv bought, some iv been gifted. I want to wash them before baby wears them of course and preferably wash them before baby arrives. However I'm just a little nervous in case I need to return them, for example the newborn clothes may not fit if baby is too big, some of the items may fit her before the season is over but if they don't I will need to return them and then the biggest IF of all is what if my baby girl is actually a baby boy!? Lol happened to my friend and she had a nightmare trying to return/exchange and buy new clothes!