Periods lasting 3weeks

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I've always had irregular periods so every 2nd month I would get my periods for 5-7days MAX!

But the last 4-5months they come after a month and half but last about 3 weeks :| I duno what's going on 😬 I wanna start trying for baby number #3 but in order to take clomid I need a proper cycle so I can take it on the 3rd day like I'm so confused :|

One week it's just brownish discharge and the rest is blood but very light and the 3rd week it's more.