Dr Wylie urges, though, that if you’re concerned about your periods, you should speak to your GP, saying: “I would also advise seeking medical advice if several periods have been missed without an obvious explanation, if menstrual cycles suddenly become much more irregular than usual, if bleeding is unusually heavy, persistent or occurring between periods, or if there is a positive pregnancy test accompanied by pain or bleeding, as these are situations where we would want to investigate further to rule out any underlying medical concerns.”
Article source: https://www.huffingtonpost.co.uk/entry/why-periods-irregular-summer-doctor-explains_uk_6a7ca98fe4b0b34a98242aef