You can get a full blood check to see if you’re lacking on any vitamins and such. I was feeling severely weak in my 1st trimester, almost bedridden and found out I was low in iron, vitamin B12, vitamin D and found out I have hyperthyroidism too, had to take separate supplements of them and medication for thyroid on top of my prenatal supplement and felt better after I started. Please do get check just in case, for your own and baby’s health.