i am 5 and a half weeks pregnant.i just had my first ulrasound.it showed a gestational sac but no yolk.i also have irregular periods.i am not sure when my last period was.when they did a ultrasound it was outside on my belly,not transvaginal.i also did not have a really full bladder and i had gone to the bathroom twice right before the ultrasound.should i be worried?

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Female , Age: 38