Weightlifting and TTC/early pregnancy

Hi, my partner and I decided to try for a child and I'm wondering what impact this should have on my exercise schedule.

I've been going going to the gym twice a week with a personal trainer and I've just bought another 10 lessons yesterday. I don't want to preventively stop training with him, because I know I wouldn't really go to the gym on my own. It might be months before I conceive anyway. But I still wonder if buying the lessons wasn't a bad idea.

I know I should probably talk to my trainer about this, but I feel really awkward bringing up the topic. He's about 5 years younger than I am and I don't really think he has much experience with pregnant/TTC clients, but it might be just my justifications why I don't talk about it with him.

Perhaps I should write to my general doctor or gynecologist?

I'm generally healthy and physically strong, but I'm 31 and overweight with sedentary job, so I'm worried that the exercise might do me more harm than good.

Do you have any advice for me? Do you know of any good study on this topic I could read?

I expect that once I learn I'm pregnant, I'll do less heavy lifting, no more badminton and will probably find some yoga instead. But I don't want to do it too early and there will always be at least two weeks when I won't know if I'm pregnant or not.