19 months of TTC/ When is it time to check everything up?

Hi everyone

Im ttc for baby 2 for about 1 year and half now. I had a early miscariagge last year in april. Every month I get nausea and very tired. I always think that I'm pregnant! It's getting me really mad when I realise that i'm not. I did the ovulation tests, the btt for month and SO told me to put that aside to get less stressed about all that.

For my 4 year old son, it took my 2 month only to get pregnant. Im gonna get 32 years old soon and my SO 35. I NEED to get pregnant soon!

Some stuff dont help and I know it... we dont "make love" everyday on my fertile window. My cycle varied every month (so is my ovulation!) betheen 27 and 35 cycle days. Im overwheight (200lbs, 5p1). Im not active. I stress a lot at my job. I could eat better and sleep more.

But even all that... is it normal that I dont get pregnant since november 2016?

What do you think? What should I do? Go see my doctor to do some fertility tests? Keep going?