I just got new saucony track spikes. My foot is exactly a women's size 6, and I ordered a 7.5 because I knew spikes run small. But when they came, I didn't know they would be that small! When I was doing a light jog my toe kind of hit the front, but it was only like one toe that reached the front of the shoe. I have like a 1/2 thumb space to 3/4 of a thumb space in the front if I move my heel all the way back. If I move my foot all the way to the front of the shoe, I have about 1 index-finger's space. They feel pretty comfy so far, but I haven't actually done any real running in them. Is this enough? How long would my spikes fit for?