Typically, the full impact of disc injuries don't really show themselves until a day or two after the actual incident, and they usually get a whole lot worse from then on. However, as Voodoo, mentions, the symptoms of disc injury can be caused by a range of injuries.
What a lot of people don't realise is that while they consider themselves fit and strong, they could be experiencing excessive bone degeneration of the vertebra's - most often caused by excessive overload, stabiliser muscle imbalance and genetics. These all contribute to the spine not being supported correctly, creating accelerated wear. This almost always comes back to poor core strength and posture.
One of the main symptoms of a disc injury will be extreme pain in the lower back and through the hips, and also sciatica pain in the buttocks, down the leg and into the foot. The patient will have poor flexibility in every direction. On the affected side/leg, will have difficulty standing on the leg for any period of time, on the balls of their heal (toes lifted off the ground) and will have decreased sensation in the affected leg (a sign the sciatic nerve is being severely impinged (lack of blood flow). Also drop foot, where the patient's foot droops and they have no control over it.
It's not uncommon you'll also experience major muscle spasms in the affected area which makes your life a whole lot worse, like what I experience in the pic below. I am standing dead straight, yet my whole pelvis has shifted to the right due to muscle spasm caused by the impinged nerve/s.
Taking a piss standing up may be difficult, as can taking a crap sitting down. If you can't piss, they almost always operate ASAP.
My number one tip is to get a referral for an MRI and pay the $300. Don't waste your time with other scans as, at best, only show part of the story - been there, done that. If the scan comes back all good, then you can rest easy knowing 100% your spine is in good health. If it comes back bad, you can get the right treatment ASAP.
The longer you suffer the effects of sciatica pain, the less chance you have of the nerve making a full recovery.
As for time off if it is a disc injury, I wouldn't be thinking of doing anything remotely strenuous for 6-8 weeks minimum. The risks of making things worse are extremely high in that period, even for several months after. My only relief from the pain prior to surgery was narcotics, laying down, squatting down or riding my sports bike - due to the knees up bent over position taking a lot of load off my lower back. Walking even 50m caused huge discomfort and increased pain. Sitting was out of the question.
I know there are people here that lift stupid amounts of weight, and I was one of them. Lifting heavy might not cause a back injury but it sure increases the risk. Knowing what I know now through personal experience, I would have taken a lot more care of my back. You only have one, when you fuck it up real good, it's never the same... ever.