Got a claim denied and I don’t know if I should appeal

Third year living in the USA (English is not my native language, sorry) due to my husband’s work, this is the first time using a health insurance not only in this country but in my whole life and I had to do a lot of research in order to know how and where to start when I found out I’m pregnant. My plan is supposed to cover ALL prenatal care, preventive tests and complications related to pregnancy as long as all the procedures are approved by my PCP, who is also my current OBGYN. Now I got a bill of $260 dollars for two preventive tests that on their website don’t seem to cost more than $40 each one, why? Cause the samples (taken at my doctor’s office during my first appointment) were sent to an out-of-network lab. I’m so frustrated cause my EOB states that as long as the tests are perfomed within an in-network-doctor’s office they should be covered. But how can I know if they are going to send the samples to an in-network lab if every time I have my monthly pregnancy control appointment they take one or more blood and urine samples and order different tests? Should I refuse to this and request that they give me an order and find the in-network labs on my own to go get the tests done? What should I do? I already had the most expensive genetic tests done and apparently they were sent to an out-of-network lab, too, so even they are covered I will have to pay for them, as well. I knew this from the name that is shown on the results sheet, I looked for the lab in my plan and it doesn’t appear (although the insurance company name does appear on the lab’s website)… I have not received an invoice yet but I am consumed with anxiety to see a bill arrive for more than 2000 dollars. I am totally lost, and frustrated, since all of these expenses wouldn’t even fit into my out-of-pocket max for this year. My doctor’s office says it’s not their responsability to check if the labs they work with are in-network labs for me, so it’s not their problem, and my insurance company states if the samples are taken within my doctor’s office they should make sure they send them to the right labs, so it’s not their problem, either. Any recommendations on how to proceed from now on? I’m heading to my 4th month and if this continues like this I will end up BROKEN.