Yep, and God basically had the Holy Spirit impregnate her while she was betrothed to another man.
She wasn't asked or given a chance to refuse -- she was told what would happen by a supremely powerful being that appeared to her. Would it have done her any good to argue? Hell, look at Zechariah, the father of John the Baptist. When he was told that his post menopausal wife would give birth to Johhny, all he did was ask "How? She's old!" and he was struck with muteness. Mary had no choice but to say Okie Dokie. It would be like if a robber said, "Give me your money, now." And I said, "Okay, here you go." And they tried to argue in court that I clearly consented, because after they demanded it from me, I gave in.