"(Mr Hreniuc) asks me if I'm pregnant, (to) which I say yes and he tells me: 'I'm not giving you this one. I can't give you this one," she told 3TV/CBS5.
After leaving the chemist in tears, Ms Mone Arteaga detailed her distressing encounter in an emotional Facebook post which has since gone viral.
"I stood at the mercy of this pharmacist explaining my situation in front of my 7 year old, and five customers standing behind only to be denied because of his ethical beliefs," Ms Mone Arteaga wrote on June 23.
"I get it we all have our beliefs. But what he failed to understand is this isn't the situation I had hoped for, this isn't something I wanted. This is something I have zero control over.
"He has no idea what its like to want nothing more than to carry a child to full term and be unable to do so. If you have gone through a miscarriage you know the pain and emotional roller it can be.
"I left Walgreens in tears, ashamed and feeling humiliated by a man who knows nothing of my struggles but feels it is his right to deny medication prescribed to me by my doctor.
"I am unsure where Walgreens draws the lines with their pharmacist but does this mean he denies women the right to birth control and morning after pill, and what's the stance with fertility drugs.
"I share this story because I wish no other women have to go through something like this at time when you are vulnerable and already suffering. I am in left in disbelief on how this can happen? How is this okay? I can't be the only one who has gone through this."
Ms Mone Arteaga has received thousands of responses, the vast majority of which have been supportive, as outrage grows over her treatment at the hands of Mr Hreniuc and people call on Walgreens to issue a public apology.
She said she later received an email notification that Mr Hreniuc had forwarded her prescription to another branch of Walgreens. Wary of a repeat performance, she asked her doctor to ensure the pharmacist at the second location would give her the medication before going to pick it up.
While Mr Hreniuc's actions seem unreasonable, hurtful and even illegal, it turns out that he was acting completely within his rights — at least in Arizona.
Arizona state law allows pharmacists to deny prescriptions based on moral or religious grounds. It is one of only six states to have that law, according to the National Conference of State Legislatures.
Ms Mone Arteaga said she called the store manager to complain and filed a formal complaint with the Arizona State Board of Pharmacy.
Meanwhile the Facebook page of the Peoria Ave branch of Walgreens where Mr Hreniuc works has been inundated with messages from disgusted customers who said they would be taking their business elsewhere in light of what happened to Ms Mone Arteaga.
"You've certainly lost this customer," wrote Kelli Sackville-Baggins.
"I won't patronize (sic) a drugstore that hires pharmacists who refuse to do their jobs. I'm having all my prescriptions, my husbands prescriptions, my daughter's prescriptions and my elderly mother's prescriptions elsewhere. I wouldn't buy a stick of gum as long as you employ pharmacists who refuse to do their jobs."
Carol Anne Teague wrote: "Walgreens I am so disappointed in you. Yes, the pharmacist gets to have his misogynistic beliefs. HE DOES NOT GET TO IMPOSE THOSE BELIEFS ON YOUR CUSTOMERS. I will not be spending another cent in your stores. You have competition. I will patronize (sic) them instead of Walgreens. I will do this until you rescind this policy."
Walgreens' corporate office is reportedly investigating the incident but admitted Ms Mone Arteaga should have been immediately referred to another employee within the store.
"To respect the sincerely held beliefs of our pharmacists while at the same time meeting the needs of our patients, our policy allows pharmacists to step away from filling a prescription for which they have a moral objection," it wrote on Facebook.
"At the same time, they are also required to refer the prescription to another pharmacist or manager on duty to meet the patient's needs in a timely manner. We are looking into the matter to ensure that our patients' needs are handled properly."