tips?

Hi everyone.
I've been using this app for a few weeks now-still getting used to the lingo and acronyms.
So I have been with my partner for around 13 years (high school sweethearts). I haven't been on the pill for at least 3 years but we still used condoms (sometimes didn't but never got pregnant).
Now we are ready for a baby and have not used protection for more than 3 months.
We are really trying now-as in I'm taking pre-conception vitamins, doing it more often, tracking my cycle on here and have gone on a diet and upped my exercise. (I am very overweight).
I am obsessed with everything baby. I have been binge watching pregnancy announcements and birth vlogs on YouTube like crazy.
My SIL is due in June with her second baby. She is the only one in my family who has had kids so far and the expectation is that I would be next. I'm 28 this year.
I have taken multiple pregnancy tests even though I know there is no way I could be pregnant. But I feel like I'm talking myself in to feeling things that aren't there and becoming paranoid about it.
My period has always been regular even when I was taking the pill and would skip a period, it would still come back regular the next month.
I am currently on my first day of ovulation according to this app so the plan is to spend this week getting busy (as much as we can with me working 5 days a week and my partner working shift work, oh and my little brother has just moved in to our house 😬).
I very rarely get sick so I never go to the doctor unless I'm super super bad (usually just tonsillitis). I know I need to go and get some blood work and make sure everything is ok but I'm a bit scared. I think that because I'm overweight I'm having trouble conceiving. But then I think that it might be my partner with the issue because he used to take drugs when we were in highschool (even though it was over 10 years ago) and maybe he's fried his goods?
I honestly thought it would happen a lot easier for me and now I think why did I bother being so cautious all these years if I was never going to get pregnant?
I just want it to happen so badly. All my friends are having babies, all my workmates are having babies and now my cousins are starting to pop them out.
My partner used to say he hated kids but over the past few years he's really become keen on the idea and loves playing around with our friends' kids. I just want to give him his own. Every couple of days he'll say to me "are you pregnant yet?" "Is there a baby in your belly?" I feel terrible that it's not happening.
Does any one have any tips?
How long did people TTC before getting a Drs checkup?
For those who are also overweight, how long did it take you to conceive?
I'm just making myself crazy but at the same time I don't want to follow up with the dr and be disappointed or told I can't have kids or something.