I lied at MEPS. Will they go back and look through my medical records?

The chances of anyone searching your pre-enlistment medical records is astronomical. What is more likely will be you having to get paperwork from your current health care provider saying you are not being treated for anything.
However, if you do not disclose this and something happens medically to you down the road you could find yourself in a terrible jam. I recommend full disclosure. If it disqualifies you find another way to serve.

I had a heart murmur and meps still let join the Army

You will not be the first! It as not until I joined the military that I learned there are so many liars in the world. During basic training 7 girls out of 33 were discharged for lying about medical conditions, during AIT another 3 were discharged. Many of these girls parents put them up to this because they thought they could get access to free healthcare. This was during Vietnam. Today things are changing. Please read my book, “Purpose Driven Thieves” that is a comparative analysis of the US method of buying health insurance vs. the UK method of buying healthcare. I hold dual citizenship between the US & UK. Many books have been written on this topic but my book is the only one that includes ‘costs’ and for decades Congress claims they would not touch this topic because they did not know how much it cost but in 2016 I gave Congress a free copy of my book. My book also offers a solution to prescription drug pricing. You probably will not get into the military but you can download a copy of my book from any online book sales such as Google or Amazon and after you read it you can contact your Congressman and ask them to vote for national healthcare and if they do not vote for it you can vote against them in 2020.

Ehh that would probably be something you wont be able to go in with. There was something I “omitted” going in and at Meps they figured it out but it wasn't a deciding factor. I had migraines before I went in but things I was exposed to made it worse so I get compensation for service connection. Your recruiter will tel you to lie and lie but that medical issue isnt something to omitt because if you are out in the field and something happens they will not have the medical equipment to help you if something went wrong. Some places will medi-vac people if it is an emergency. But they can give you dishonorable discharge will can affect getting a job on the civilian side

Dude, a simple Doctor's note can clear that if you're in good health, but blowing your own whistle here on a public site is a No Go. Especially before you even know what your current status is. Take a deep breath and relax, you won't go to Leavenworth for this one. I'm sure you're fine if you already passed Basic and AIT

They will now. Lol

No. Lol everybody lies at MEPS whether it’s a small lie or big lie. Don’t listen to the assholes on this post. You’ll be okay.

in the world today the truth can help or it can hurt you, do the RIGHT THING.???

Good things there's no recruiters on this forum....lol

So you are saying you know what was in your medical records at age six. How did your parents tell you? I don't know Jack about my medical records before highschool. However you did and now you admitted to lying on federal government paperwork on social media. I wouldn't hang my hat on getting into the service.