Think I’m unable to conceive

So I’ve been with my boyfriend for almost 3 years now and we haven’t got pregnant yet . I’m not sure if it’s because I’m only 19 because he has a child already . I’m sure I have grown enough to produce i have periods so what am I missing I really think there is something wrong with me my periods are irregular & I have lil pains where my ovaries are sometimes what should I do !!! 🥺