A few different things could be going on. Here are the most common culprits of a missed period with pain when you're not pregnant:
- You have a urinary tract infection. Do you have a fever or pain when you're urinating? Keep an eye on your symptoms and if they continue or worsen call your doctor. Urinary tract infections are easy to treat but will make you feel awful the further they're allowed to progress without an antibiotic.
- You ovulated late and your period is gearing up to start. If you don't have any other symptoms of a UTI, chances are that you just ovulated late and your period is about to come on. Lower back pain is sometimes a pregnancy symptom but it's also a common PMS symptom.
- You're pregnant but it's too early to test. For some of us, we'll feel a plethora of symptoms and even miss our period before a test shows up positive. It comes down to how quickly the pregnancy hormone builds in your system and it's possible there's just not enough of it built up yet to give you your BFP.