Second, yes, you *will* notice if the condom ripped or fell off. To check for tears, you can *properly* remove the condom after sexual intercourse and then fill the condom with water. tie it up and then look for water leaking out.

As for the hand job (manual sex), you can transmit an STD if both you and he have open sores or cuts on your skin. Even small cuts -- the kind you don't even notice -- can transmit disease. This is why it is ultra-important to roll a condom on him as soon as he's hard. however, unless you rubbed his semen on your vulva during/after manual sex, you aren't going to get pregnant.

As far as your itching, swelling and discharge, if you don't use additional lubricant with your condom, you can chafe your vagina during sex. Use water-based lube; not only does it feel so much better, but it also makes it less likely that the condom will break. Itching could be an infection, which will require a doctor visit. Swelling could be infection, of chafing. In either case, if you are not feeling any better within 3 days after sex, you should call your doctor and see if you have any sort of infection.

You can buy pregnancy tests for around £10.