### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
im an 18 year old girl that has been having this weird pressure in her lower back which makes it difficult to sit for long periods of time. this has been happening for a week now together with nausea, thirst, fullness in the lower abdomen, diarrhea, and fatigue....im not sure if this could be because of stress or because i might be pregnant but the possibility might be very slim since last time i was active we could not do anything since it was painful and he came but with a condom

### output:

If you had sex with condom then it's not possible that you get pregnant. As well if you have got period after that then its conform that you are not pregnant. Here you need to check your back pain started after abdominal problem or before it. If back pain started before abdominal issue then back pain could be different and abdominal pain could be different.However the conformation will.be done by physical examination and few tests. So I suggest you to visit specialist and get your self examine, here for back pain if it is from long time with radiating pain to legs doctor will ask you for MRI of back. As well for abdominal discomfort, heavy less and nausea you need to do ultrasound abdomen. Based on report you can discuss it with your specialist and plan for treatment. In general here still till the time diagnosis is not conformed I suggest improving your food habits by having good amount of water and fruits in your diet, avoid spicy food. At the same time for your back use hot pack to relax the soft tissue. This will also give you some more relief. As per your explanation looks like you have got disturb gastrointestinal system and due to that you have diarrhea and due to that more pressure on back muscles there is heaviness feeling too.However the conformation will be only by physical examination and needed tests. Take care