Ive took an allegra-d 24 hour last night around 10:30pm. it is 3:40pm now and my allergy problems have barely improved. would it be okay if i took another pill?

Be patient. Allergy pill especially long-acting one takes time, 2-3 days at least, before you really feel a full effect.

For most people, Allegra-D starts working about one hour after taking the first dose and provide about 24 hours of relief. Regarding a second dose, waiting until closer to the 24-hour mark is best, although if there is still no relief after, further evaluation by a healthcare professional would be beneficial, as the symptoms could be due to another cause or additional treatment may be appropriate.