Of course, when we eat and drink, that is when we receive it (we haven’t received it until then). When it becomes the body and blood of Christ is at the time of consecration.From the LCMS site:
“In view of these (scripture) passages as well as the words of Jesus when He instituted the sacrament, we have concluded that while we eat bread and drink wine in the sacrament we–in, with, and under these forms–receive the body and blood of our Lord. How? That is the mystery.”
The mystery is how it is changed. Yes, Lutherans express the mystery as “in, with, and under”. Catholics express it as Transubstantiation. The fact that it is changed at the time of consecration is not an issue between us.
The ecumenical discussion has shown that these two positions must no longer be regarded as opposed in a way that leads to separation. *The Lutheran tradition agrees with the Catholic tradition **that the consecrated elements ***do not simply remain bread and wine but by the power of the creative Word are bestowed as the body and blood of Christ. In this sense it also could occasionally speak, as does the Greek tradition of a “change”.36 The concept of transsubstantiation for its part is intended as a confession and preservation of the mystery character of the Eucharistic presence; it is not intended as an explanation of how this change occurs37 (see the appendices on “Real Presence” and “Christ’s Presence in the Eucharist”).