As you no doubt know, the three stars on the Virgin’s maphorion (mantle) in Orthodox icons—one on Her head, and one on each shoulder—are intended to signify Her perpetual virginity: (1) before, (2) during, and (3) after the birth of Christ.
The “during” often puzzles people: “before” obviously means that She had no sexual relations with a man prior to Christ’s birth, and the “after” that She had none later. But “during” seems odd; clearly no woman is going to engage in intercourse while she’s giving birth. The second “star” has therefore often been taken to refer to what’s going on with Mary physiologically when Christ leaves Her womb, and thence to the claim that Her hymen remained intact and unaffected. This, if I understand you correctly, is the backdrop to your question: Did Mary experience any pain in childbirth?
Of course, what the Church won’t allow us to say (and for very good reasons) is that the birth was not a real birth. Although Christ entered Mary’s womb miraculously, His exit was such that, if we’d been there, we would have seen a little body coming out of His mom’s birth canal, just as all babies do. No docetism allowed … no preternatural “birth” of an Athena from the head of some Zeus. You can talk about the birth being “a type of ecstatic experience, God coming-out-of-the self” (your phrase), if you want, but it’s important to insist even so that genuine bodies were involved: a mother’s body and a baby’s body; whatever it was that occurred, it had an impact or a “resonance” (if you will) on multiple planes, including the material.
This, by the way, is why some Orthodox iconographers, while showing two stars on the maphorion, deliberately paint the Child’s body in such a way as to conceal the third. The third star remains proportionately or symmetrically implied, as it were, but the fact that it can’t be seen helps to “offset any suspicion that a virginity in partu might render the birth of Christ excessively ‘magical’ and docetic…. In this the theologian-iconographers’ … instinct for Orthodoxy was unerring” (John Anthony McGuckin, The Orthodox Church: An Introduction to Its History, Doctrine, and Spiritual Culture [Blackwell], p. 215).
In any case it’s important not to get too caught up in thinking that the Virgin’s perfection, or that of Her Child, made Her immune to pain pure and simple. Perhaps the birth process, given Her perpetual virginity, was other than the unusual, as I’ve noted above, and perhaps it therefore didn’t cause Her physical pain. Nonetheless, let’s not forget the prophecy of Simeon: “A sword shall pierce through thine own soul also” (Luke 2:35). Whatever that means, I’m guessing it really hurt.