So my 98 s70 had a motor oil leak until a mechanic fixed te drain bolt and it no longer leaks. Well for some reason when I check the motor oil stick it shows below the x's? is it because the car is hot? Or do I have a leak or pressure problem

 

The x's are the safe range. Add enough oil until it is near the top of them then check it every day or so. If the level drops you have a leak that you'll need to locate and fix.