For back pain in your third month, Acetaminophen (Tylenol) is the safest oral pain reliever to use. You must avoid NSAIDs like ibuprofen, naproxen, or aspirin, as they can carry risks during pregnancy. For topical relief, applying warm or cold compresses is highly recommended and completely safe. While mild menthol-based ointments can be used sparingly, avoid any creams containing salicylic acid or prescription anti-inflammatories. Non-pharmacological measures like gentle stretching, prenatal yoga, and wearing supportive footwear can also offer great relief. Always consult your OB/GYN before starting any new medication or ointment.

Irregular periods for just one month can be caused by temporary factors like stress, lifestyle changes, or minor hormonal fluctuations. There is no single over-the-counter medicine to safely regulate your cycle without identifying the root cause first. Depending on the diagnosis, a doctor might prescribe oral contraceptive pills, progesterone therapy, or thyroid medication. I highly recommend consulting a gynaecologist. They will likely perform a physical exam, ultrasound, or blood tests to check your hormone levels and determine the correct, safest treatment for your body. Please avoid self-medicating.