Could Pain In Lower Back After Bending Be Muscle Related Issue?

i was bending over yesterday to clean my bike and all of a sudden i had a lower back pain. I instantly sat down and when on google to search some lower back stretches. I woke up this morning and i still have lower back pains. Todays saturday but on monday im gunna go to my doctors to get it checked out. Im just wondering how could i tell if it is a spine or muscle related issue? thanks!!!!! btw im only 19 years old and i've been working out for 3 months now so im not overweight...