Im 12 weeks pregnant with my second child, they upped my dose of levothyroxine to 224, could it cause me to have diarrhea?

Not likely: You don't say what your dose was previously. 224 mcg is a large dose for most people. If you are hyperthyroid as a result of too high a dose, this could cause diarrhea. You need to be sure to take it on an empty stomach, wait 40-60 min before eating. You also would be best off on a brand-name medication, such as synthroid, (thyroxine) unithroid, tirosint, as there is less variation in how it works.

Yes: Thyroid excess can result in diarrhea a scan primary hyperthyroidism.