Hi, I understand your query & concern. Sinusitis is infection of sinuses. It is inflammation of sinuses following sever common cold. Management should be- - Taking antibiotic/ anti inflammatory drugs with expert advise of an ENT specialist. Amoxicillin you are taking harmless in pregnancy. It is better to take the dose prescribed at a stretch- to finish the infection completely. Taking antibiotics with breaks in between- may create bacterial resistance. Anti allergics are contraindicated in early pregnancy, instead nasal budacort spray may be given for a short period if expert feels it needful. Thankss - Avoiding exposure to allergens/ too much of cold/dust/helps. Inhalation of medicated vapor helps in reducing inflammation.Nasal blowing should be avoided. _ vitamins ( B,C Thanks.