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If you take a pregnancy test 2 days before a period it may be negative. In fact it is often negative even if there is pregnancy. If you suspect you are pregnant repeat the test after your due date if you miss the period.

Hot flashes or heat coming on and off generally in one limb like in your leg is usually a sign of deep vein thrombosis. A color doppler or an angiogram is able to diagnose the condition. Smoking is a complete no for this condition and caffeine should be reduced to minimum. You need to consult a vascular doctor for this. Hope this helps. Take care!