If you're trying to get pregnant, it's time to learn to evaluate the severity of symptoms and make important decisions about where best to get care. That means for you, and ultimately for a baby, for whom you will make choices about seeking care for every fever and rash.
So, you have a lot of symptoms that could be related to being pregnant, but could be related to lots of other things, including monthly hormonal changes, or a UTI. Now, for some unexplained reason, you decided to go to the ER for groin pain, instead of contacting your physician. Do you have a doctor? If you are trying to get pregnant but don't have a doctor or a Planned Parenthood clinic, why not? If it was a weekend and your doctor wasn't in the office, that's one thing. But you could have gone to an urgent care center or walk-in clinic. There are many of them in Terre Haute - just Google "walk in clinic" or "urgent care" and your zip code. You would not have waited so long, it would not have been nearly as expensive (to you or your insurance company), and it would not have delayed emergency physicians from attending to patients with dire emergencies. You cannot use an ER for regular care - and that is essential for anyone who wants to be a parent. So re-think that for the future.
You say they didn't do any tests. Really? Then how did they diagnose your UTI? Did you give them a urine sample? I'm guessing you did. I cannot believe that they prescribed antibiotics without some indication. Did they palpate/press on your abdomen? Then they did something to diagnose you. What did you want them to do, given that you hadn't contacted your own physician? They determined that you were not having an emergency, and they sent you home with appropriate treatment.
Did you tell them you might be pregnant or at least were trying to conceive? If not, re-think that. I'm guessing they asked you if you were pregnant. In fact, they might have run a pregnancy test on that same urine, and you just don't realize it. You must tell every medical provider as well as your dentist that you are trying. You ask if every treatment and medication is appropriate. When you get a medication from your pharmacist, you verify that it's safe for pregnancy. What you don't do is get the medication and then go home and decide not to take it. That can be more harmful to you or a fetus. You don't have to know the answers; you just have to ask those who are knowledgeable.
So, instead of getting all nervous and anxious, make 2 phone calls.
1) Call your doctor to explain your symptoms and ask if you should be seen. I'm guessing that the ER asked you the name of your primary care physician (either in person or on the forms you filled out) so your records of the ER visit will be sent to that MD. If you don't have a doctor, call your insurance company and ask for a referral. Usually they don't give insurance without you indicating who your PCP is (primary care provider).
2) Call your pharmacist - wherever you got the antibiotics - and ask if this particular medication is safe for someone who might be pregnant. You can ask the same question of the prescribing doctor or your PCP.
Beyond that, I'd suggest you enroll in a parenting class or first aid/CPR class so you start to learn about medical issues, how to care for a child, and so on. Call your local library, adult ed/vocational school or community center to see what's offered locally and in the evenings after work.