Backache is normal as your baby is growing and getting heavier. Just be prepared backache will worsen as you go into trimester 3. You can go for pre natal massage once you hit your 5th month. If you need to eat medicine for headache, make sure you are eating the basic paracetamol. Only take pregnancy safe medication. Do not take panadol extra as it contains caffeine. If unsure, best to consult a GP doctor or your gynae.
Having headaches too and asking hubby to press my head for me, usually when I lie on one side for too long. For backache I watched YouTube videos online on pregnancy posture and it helped me. Going to Physio as well for advice on my posture.