Dehydration; She was vomiting during the phone call to report the AE; Felling like she was burning up/hot/felling very very hot; Felling sick; Chest pain; Not been available to sleep; Severe pain in the arm, she cannot move it; Nausea; Vaccination site pain; chest pain; Pregnancy; This spontaneous prospective pregnancy case was reported by a consumer and describes the occurrence of INSOMNIA (Not been available to sleep), PAIN IN EXTREMITY (Severe pain in the arm, she cannot move it), FEELING HOT (Felling like she was burning up/hot/felling very very hot), ILLNESS (Felling sick) and CHEST PAIN (Chest pain) in a 21-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 020f21a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included COVID-19 (Hospitalization due to COVID-19: No, sick for about a week Treatment received was Tylenol) on 12-Sep-2021. Concurrent medical conditions included Drug allergy (allergic to oxycodone) and Asthma. Concomitant products included MINERALS NOS, VITAMINS NOS (PRENATAL VITAMINS [MINERALS NOS;VITAMINS NOS]) and DOXYLAMINE SUCCINATE (UNISOM 2) for an unknown indication.    On 01-Oct-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. The patient's last menstrual period was in June 2021 and the estimated date of delivery was 08-Apr-2022. On 01-Oct-2021, the patient experienced INSOMNIA (Not been available to sleep), PAIN IN EXTREMITY (Severe pain in the arm, she cannot move it), CHEST PAIN (chest pain), MATERNAL EXPOSURE DURING PREGNANCY (Pregnancy), NAUSEA (Nausea) and VACCINATION SITE PAIN (Vaccination site pain). On 02-Oct-2021, the patient experienced FEELING HOT (Felling like she was burning up/hot/felling very very hot), ILLNESS (Felling sick), CHEST PAIN (Chest pain) and VOMITING (She was vomiting during the phone call to report the AE). On an unknown date, the patient experienced DEHYDRATION (Dehydration). The patient received mRNA-1273 (Moderna COVID-19 Vaccine) beginning around the  thirteenth week of the pregnancy.  At the time of the report, INSOMNIA (Not been available to sleep), PAIN IN EXTREMITY (Severe pain in the arm, she cannot move it), FEELING HOT (Felling like she was burning up/hot/felling very very hot), ILLNESS (Felling sick), CHEST PAIN (Chest pain), DEHYDRATION (Dehydration), VOMITING (She was vomiting during the phone call to report the AE), NAUSEA (Nausea) and VACCINATION SITE PAIN (Vaccination site pain) outcome was unknown, CHEST PAIN (chest pain) had not resolved and MATERNAL EXPOSURE DURING PREGNANCY (Pregnancy) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On 15-Sep-2021, SARS-CoV-2 test: positive (Positive) positive.     The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   No treatment medication was provided.  Ultrasound and EKG were performed on patient for myo/pericarditis but did not find either and it also included fluids as treatment.  Patient did not had history of myocarditis/pericarditis.   Most recent FOLLOW-UP information incorporated above includes: On 05-Oct-2021: Live followup received on 05-OCT-2021 included: added patient history and lab data and events and updated narrative accordingly.; Sender's Comments: This case concerns a 21 year old pregnant female at 13 weeks gestation with an LMP of end of June 2021 and an EDC of 08 April 2022 with a history of COVID-19 infection 12 Sep 2021 that resolved prior to vaccination and experienced the AESI of Maternal exposure during pregnancy and other non-serious listed and unlisted events occurring the day of the first dose of mRNA-1273 vaccine. Re-challenge is unknow as the second is not yet indicated. The history of COVID-19 infection remains a confounder as this could have enhanced the reaction and severity of events. Benefit-risk relationship of mRNA-1273 is not affected by this report.