Depends how much you were walking before I guess. I haven't done much since falling pregnant as I'm so tired but try to walk when I can for 30 mins or so.
I walk for 30 mins at a time making it twice daily.. is it enough walking..I do it after meal daily...but now the problem is. .as I m in 7th week now.. I get backache too.. my walking is reducing. .
Just do what you can. Don't be too hard on yourself. 30 minutes twice a day is more than I do and probably more than a lot of people. Don't worry about specifics too much, just try to stay active.
Focus more on just moving in general then a set time. Also if you weren't doing anything before getting pregnant don't try to push yourself too hard now. First tri can be tough with exhaustion but find what works for you. I find if I go running or spinning first thing in the mroning it's easier than later in the day.
Re: walking
so tired but try to walk when I can for 30 mins or so.