All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
There is some ambiguity in the question, so we do not know what is the problem exactly. If you mean that an Islamic marriage contract with this woman has been conducted between you and her, with the permission of her guardian and the presence of witnesses, then the marriage is valid, and by this, she has become your wife.
If you have consummated the marriage with her after the contract and before the wedding date, then this does not affect the validity of the marriage, and this pregnancy is attributed to you. If there is a custom of delaying the consummation of the marriage until the wedding feast takes place, then you should have taken this into account.
If the confusion is regarding the delay in paying the rest of the bridal money, and you are asking whether or not this invalidates the marriage, then the answer is that it does not invalidate it. Rather, the marriage is valid even if you did not name a bridal gift for her at all.
But it is desirable to name the bridal gift before the marriage contract. This is the Sunnah of the Prophet in his marriage, and because this puts an end to any disputes.
If you are asking about something else, then please clarify it to us.
Allah knows best.