Trying to get pregnant

Well I'm 20 and my boyfriend is 24,

We have two handsome boys we want another one

But it seems its taking forever I've spent hours on YouTube an Google trying to find the best way to get pregnant with my two boys they came easy but why my third has to be sooooooo hard

Am I doing some wrong or do yall think I'm trying to hard honestly

I'm starting to get annoyed an I hate to see negative pregnancy test its been almost a year

????

An still not

Can I get any tips or which way is faster