Hello dear! I have gone through your query and understood your concerns! Thank you for sharing them on healthcaremagic. Regarding to your question I have to say that there are no interactions between this two drugs or major side effects that would harm your health. You can use them together, try first 500mg of acetaminophen and if you can t control your pain with that dosage then increase up to 1000mg. Another option would be ibuprofen 400 mg which is also very helpful with menstrual cramps and pains. Always take these drugs after meals and with plenty of water. I hope this answer was helpful to you! I would appreciate a lot if you rate as helpful my answer and write a short review about your experience with me. Thank you and best regards! DR ERIOL