Vitamin C during pregnancy?

Hi ladies, wanted to get a second opinion as I don’t have a fixed gynae. Did any of your gynaes tell you if it’s ok to take vitamin c (like those 1000mg effervescent tablets)? Before pregnancy, I always took it and found it to be quite useful in preventing sickness. I’m not so sure now that I’m 7-8 weeks pregnant 😅 Anyone knows? Trying to build up my immunity :p