Nipple sucking - TMI

So when im not pregnant, I can’t feel a thing and its not enjoyable. We got pregnant (ended in a loss at 11 weeks) but that’s how I discovered how much I love having my nipples grabbed and sucked during sex! I’m assuming it’s because they were sensitive. After the loss obviously we were mourning didn’t try it for months but eventually when we did my boobs went back to normal/ not sensitive.

I’m pregnant again and it’s back. I’m worried about when we should not do that anymore... can’t it trigger labor later in the pregnancy ? I also wouldn’t want to trigger milk production before baby arrives ?