numb/minor pain

I've got minor pain in my hamstring (i didn't pull it or anything during exercise), minor pain in my lower back ( progressively started to feel it over last couple of days) and my left arm feels slightly numb. For some reason i think its connceted cause it all happend after heavy overhead presses. Pinched Nerve ?

Numbness is slowly going away (SLOWLY)

It may be a pinched nerve, did you feel any twinge in your back as you were doing them? were you standing or sitting? and dumbells or barbell?

I use my belt now when I'm doing heavy standing overhead presses as I twinged my back once. Now I put the belt on when I start getting into my heavy territory and haven't hurt myself since.
Be careful with your back mate, the numbness you have is a bit scary, don't go hammering the weights until you have either releif or seen the doc. It may be nothing to much to worry about, but veer on the side of caution to be safe.
Good luck with it mate.

yeah i think i'm going to drop standing overhead presses and do them seated with a slight decline. To be honest the only twinge i did get was from t Bar rows.

and that was in the shoulder

Mate don't stop doing SOHPs, just wear a belt and focus on using less weight to begin with as it really works your core muscles heaps. Once you build up your core, you'll be able to smash some bigger weight over your head no probs. Just start with a moderate weight and supplement with some seated dumbbell raises to begin with.

But wait until your healed up first, don't over stress your back. Hope that helps you mate, sux getting injuries.

EDIT: Also, make sure your really squeezing your abs/core when doing them so you take the stress off the back, you should have sore abs after a good session of SOHPs, as well as smashed shoulders too. It's to good an exercise to not do them.

Numbness in your arm relates to either brachial plexus (large nerve center near your shoulder) injury or upper spine issues (unless the problem is only in your forearm). Go get it checked and do not do any overhead work. The back pain could be related to a spinal issue or it could just be an unrelated separate issue. Hamstring is in the same boat.

Since all 3 came at once I would go get it checked and they will assess your cervical spine for any issues. This could be a herniated disc, vertebrae fracture, posture issue, nerve blockage etc etc.

Stop lifting and get it looked at to be safe.

its weird i don't know if its numbness or xtreme tightness. If i prick my fingers i feel it, run under cold water it feels the same both arms.
It really feels mainly in the forearms and the tigthness goes around to my rear delt and lat.
I put a heat pack on my shoulder and the numbness or tightness goes and the arm feels great.
Was doin external rotations and the range was pretty poor. I've had major stability issues with this shoulder and it has been lagging.

i'm going to goto the doctor as a precaution, it's just bloody expensive

I think that's a good idea mate, dave has highlighted some good points of interest there, better to be safe than sorry mate. I know it's expensive, but money comes and goes mate, your health is the single most important thing in your life, if your not in good health the cost then flows onto/into every other aspect of your life.
Hope all is not bad mate, keep us updated.