Yeast infection treatment?

so I bought miconazole 3 ( a cheaper version of monistat) anyways I'm supposed to take 1 nightly for 3 nights..I used one today as soon as I bought it..I'm just curious, I'm heading to bed soon and wondering if it is safe to use another one tonight instead of waiting until tomorrow night?? It's been about 8 hours since I used the first one.