43 days late! no symptoms and negative test!need help and advice!

kylie

okay so i skipped a period in december and got one in January and they’ve been like max 5 days late or early since then and then in june i didn’t get a period i texted after 35 days i was negative both line and digital and ive been feeling like my perfectly normal self! i didn’t start my period in july either! my sister is a nurse and she said to wait at least to see if it comes in august and if not go to the dr since it’ll be 3 months! but i’ve never been diagnosed with pcos or endometriosis or any hormonal issues but can they come out of no where or develop over time? i have no symptoms at all and feel perfectly normal and i have negative test! so i just don’t know what could be going on i don’t think im pregnant but i fear it might be pcos or some kind of hormone issue! has anyone had this happen before? if so what was the outcome?