I’m type 2, 15years, been taking Metformin 500mg twice a day for about three years. Ive started using a Libre 2 sensor, this is my third weeks It estimates H1abc at 5.9mmol. I’m following a low carb diet. Today after a bike ride this afternoon my numbers have plummeted to 2.8 and fluctuated around up to 4.2 and now back to 2.9. I’ve eaten a couple of rich tea biscuits, some diabetic chocolate even a gin and water but numbers still down. I’ve never seen these red band readings before. Tried to check the readings with my Free style meter but I haven’t used it for so long it’s defunct. It’s the same one they gave me 15 years ago. Have changed battery. Should I be concerned?