Do you think I have the flu despite getting the flu shot?

I got the flu shot in late October which is plenty of time for the antibodies to kick in. However my entire family is unhealthy and they're all sick. I theorize this made my flu shot irrelevant. Last night, I was sure I had a fever. Somehow i was hot and cold at the same time. When I say that, I mean my torso felt like it was very cold and my arms were shivering but my legs were overheating. I've had little nausea and my joints have been hurting. This morning I was finally able to get a thermometer to check my temperature and it was 99.5 F and I don't feel that bad compared to last night. And I have a terrible cough.
Do you think I have the flu despite getting the flu shot?
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