Hello,
Symptoms of pregnancy are the same whether you are using Mirena or not. The first missed period as the first sign of pregnancy, but a missed period can be caused by a number of factors. Some women experience spotting about two weeks after the first day of the previous period as the first sign of pregnancy. Changes in mood is caused by hormonal surges early in pregnancy can be quite severe. Often this is the first symptom of pregnancy noticed by family members, Pain in breast and enlargement is especially common during very early pregnancy, but often disappears after a few weeks. The area around your nipples turns dark. Tiredness, nausea and vomiting, sometimes referred to as morning sickness, ranging from queasiness to severe vomiting that can manifest just in the morning.
If you are having such symptoms then you should get your pregnancy status.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Symptoms of pregnancy aren't different if you're on birth control or anything. Symptoms of pregnancy are very similar to symptoms of PMS or just side effects of birth control. If you suspect you could be pregnant then you need to take a home pregnancy test with first morning urine and see what it says.
If it's negative and these symptoms continue and no period then you would need to see the doctor because it could be mirena working against your body or something. It's also possible that your body is just preparing to start a period - it can happen even while breast feeding.