I went into our local bike store and my husband and I talked with an employee there about getting road bikes. My husband is 5' 8" with a 32" inseam and I am 5' 7" with a 31.5" inseam. The man in the bike store kept telling me I should be riding a 56cm road bike and kept telling me to test ride that size. I did and it felt okay but it did feel like I was too stretched out. I really thought I should be on a 54cm but the man kept insisting I should be on a 56cm. I went against his judgement and bought the 54cm and have had it now for quite awhile and I just love it. It fits me perfectly and every other cyclist and bike store employee I have talked to has told me I should be riding the 54 cm. That same employee also insisted upon my husband riding a 56 cm but he also bought a 54 cm because to him it just felt much better. The point being... just because a bike store employee tells you that you should be riding a certain size doesn't mean they are always correct. You should test ride both the XS and S sizes and see which one feels better to you. Is there another store in your area that would have the S size in stock for you to try out?