When should you start taking bird nest and how much? Must be be fresh or can drink canned

I drank the fresh ones that my mum made for me every week but I portion them to take over 3 or 4 days. I think at least you know how much bird nest is in the fresh one and how much sugar you put in it. There are also no preservatives. I took it during 2nd trimester and stopped at 3rd. No reason why just got sick of it.