About using of my regular Medication.

I'm 4 months pregnancy my LMP-21/10/23, I have detected thyroid during pregnancy. From the last 6 years I am using Montek LC for dust allergy I have intimated my regular gynaecologist about using Montek LC tablet on daily basis. She said no issues by using that. Recently I went to our department Gynaecologist for normal check up, she asked about my medication and I intimated her about Montek LC also. But she told me to avoid using that in regular basis. Now, I'm little bit confused to take that medicine or otherwise. Please suggest whether I can use it on regular basis or otherwise. And if I don't use it on regular basis I will have running nose, regular squeezing etc. Is there any other medication to replace the above medicine pse suggest it. Also presently I'm using Fur-XT tablets as my doctor suggested. Now, I got my tablets from CGHS dispensary they gave me Ferron - CR in place of FUR-XT. Pse suggest me whether both tablets are same and can I use Ferron-CR in place FUR-XT.