I'm having a sharp pain that feels like it's coming from the top of my lateral incisor...?

There's a sharp pain coming from my lateral incisor on the side where it meets my central incisor. It hurts especially when I run floss over it. Is it a cavity? I don't have dental insurance, so what can I do about it?
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Im might be a cavity, as im might be something else. One sure thing, if you dont get it fixed and there was a cavity, it will only be more expensive as you wait. Example: - First you get a cavity -> 80$ to fix - You wait, then it gets bigger -> 200$ to fix - You still wait, then you get an infection -> 500$ to treat - You wait, using antibiotics -> the infection get worse, the tooth is unrestorable, so it now cost 100$ to extract the tooth. - You wait cause you dont want to loose the tooth and dont want to pay 100$, so the tooth break down to gum-line -> its now 250$ to extract. - You now want to place an artificial tooth there -> 300-3500$ to do. You can easily understand that there is no better time than going sooner, as its cheaper and you get to keep your tooth
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