Can you still have unprotected sex when pregnant?

You can do a lot of things. Some of them might not be good for you.

If the reason you were concerned about protection was to avoid getting pregnant, then sure; what's going to happen, you're going to get MORE pregnant?

If, however, your concern was sexually transmitted diseases, then it's probably a good idea to go ahead and continue with the protection.

In all cases you should probably ask your doctor first. There might be reasons it would be best for you specifically to abstain for the duration of the pregnancy.