IPhone 4s keeps on charging and uncharging when we barely move it?

I have an iPhone 4s and when i charge it, the slightest movement makes it uncharge then charge again then uncharge and so on. I thought it was just the charger but I switched chargers and it still does that. My old htc wouldn't charge anymore and now my new phone is having charging problems and I don't want my parents thinking I can't take are of my phones because I'm literally not doing anything to make this happen, also my hp windows 8 computer is going slow and won't stop sending norton security alerts to download it and ugh I just have bad luck with electronics. So why won't my iphone charge properly?

Something's up with either the outlet you're plugging into, or with the charging port on the phone. You might need to get it looked at by Apple. Although I'd say it's probably the outlet, seeing as you've had this problem with your old phone too.

Oh no. This always happens to my Kindle fires. Try to get a new charger. If that doesn't work then it's the area on your phone where you charge it. DO NOT MESS WITH IT though! Trust me, it makes it worse. Try going to an electronics store to see if you can get it fixed. If you can't, replace it with warranty or buy a new replacement. OR try to charge it by your computer/car/laptop/etc.