Is your window on ground/first floor? What did doctors say? What was blood loss caused by?

Your experience reminds me of a few NoSleep stories (for example: https://www.reddit.com/r/nosleep/comments/2ugtmq/theres_a_man_on_my_balcony/ https://www.reddit.com/r/nosleep/comments/rsdy0k/the_glowing_red_eyes/ https://www.reddit.com/r/Paranormal/comments/10byjic/hooded_figure_on_the_porch_couch/ https://www.reddit.com/r/nosleep/comments/2by83n/there_was_a_woman_at_my_window_last_night_asking/) and the scene from the movie "Salem's Lot" (1979), where the friend shows up at the window asking for him to open the window.

A nice salt line in front of your windows/doors (you can also make a giant unbroken circle around the bed for additional protection. Salt has long been considered pure and used as a preventative to supernatural occurrence. Sandalwood is another good resource), a nice motion activated camera, a nice phone call to the police explaining the timeframe(s) when the tapping most recently happened. Let them know you awoke to knocking, found the prints the following day and are concerned it was a potential break-in. They will know if there have been any robberies in your neighborhood or even sketchy people they have run-ins with. If it's a smaller town, they will also probably drive by a few times for the next couple of nights just to keep their eyes out for anything sketchy. (god-forbid something did happen like a break-in) It will start a papertrail and provide useful info, as it's not uncommon for a house to be cased prior to the actual crime.

I also recommend this one method of catching your stalker: when you suspect someone is outside and it's dark, or even if it's not dark but you see something weird, just take pictures as those will always be helpful.

Additionally, you can:

• Download an app on your phone that records as soon as it detects motion (if you want this, I can try to find the name!);
• Put some glue traps outside the window, so hopefully he will leave physical evidence behind when he shows up again;
• Get/have a dog or dogs is a known deterrent for criminals;
• Get a can of wasp spray. It works like pepper spray only you don't have to get too close and it's harder to get off;
• Also, get a baseball bat. You will be amazed how fast and hard you can swing that thing when you are scared and over it.

If things are getting worse, don't scream/call for help, scream "Fire!". My mother taught me to do that, she always said people move quicker when their lives and property could be at risk.

I really hope you're ok, and please keep us updated!