Hi so my son turned 3 in Feb and has slight speech delay (just in case it has anything to do with this).
Anyway. Month or so, since starting at a new daycare (may have something to do with it?) he is always pinching, slapping and hitting (bites sometimes too). And not randomly, usually does it when he does not get his way or I try dress him when he doesn't want to be dressed etc.
He pinches really hard. And he gets this look on his face that he is really trying hard to hurt you.

So for example i'll be trying to get him dressed, he does not want to get dressed so starts kicking me and pinching me and being a little terror! Or comes up and slaps or pinches when you turn the tv off or take something away from him when he doesn't want it to happen.

I have no idea what to do!

I have tried time out, which is a major fail as he does not even stay there no matter what I do.
Tried ignoring him, telling him it is wrong and he hurts.

Has anyone been in a similar situation? Is it normal? Please help!

My nephew was a biter and my son a hitter.
Make sure he understands that 'we NEVER bite/hit/scratch - it hurts mummy and is a nasty thing to do - please say sorry and don't do it again".
Think up consequences for hitting, pinching or biting and be consistent. Have a little chat to him at a time that he is receptive and warn him that from now on there will be consequences for doing those things and tell him exactly what they are so he understands.
Taking favorite toys away and putting them in the top of the wardrobe for the day is one that has worked for us.
Alternately, if he won't stay in time out, and if you can close the door of his room and he can't get out, I would consider doing this for short periods, i.e. 2 minutes.
If he does this to another child or to yourself while you are out doing a pleasurable activity, ie. at the park or on a play date, give him one warning, and if he does it again then go straight home.
Encourage him to 'use your words' if you can see his frustration building up. Also praise him a lot when he does cooperate when getting dressed, or doesn't make a fuss when he might have done.

Sometimes giving some lead up to what you are doing can help so that it doesn't come as a surprise.
For example say "In five minutes I'm turning the TV off", then after a couple of minutes "Nearly time for the TV off" then OK, it's time for it to go off now" when you actually switch it off.

That lead up gives them time to come to terms with what is about to happen, rather than it being a sudden event that they react to IYKWIM

Our son turned 3 in March and also has a speech delay. He started childcare recently and that has coincided with him hitting as well. I figured it is just a stage, tell him it's wrong to hurt people and we NEVER do it and otherwise ignore it.

My DS was 3 in March and has always been a little bit rough but he is getting better.

I would tell him that what he is doing is hurting mummy and that mummy loves kisses and cuddles instead. He also loves cuddles so it has always worked well for us.