Thanks for the query.
Among the contents of the Flanil
cream, Methyl Salicylate
belongs to category C drugs in pregnancy
according to FDA. Menthol and Eugenol are not categorized.
So in overall we can take the cream as category C drug.
Means animal studies proved some adverse effects but studies on humans are lacking.
But as you are using only for limited period of time and as you already crossed the first trimester in pregnancy possibly there may not be any much harm to the baby.