API请求GET延迟

看，我做了一个接收用户CPF的代码，然后将其发送到服务器，它检查CPF是否有效，如果有效，则在控制台中打印用户名，如果不是，则打印“ Not Found”，这是代码：

cpf.component.html

<form class="ion-padding-horizontal">

  <ion-list>

    <ion-item>
      <ion-label position="stacked" color="primary">Insira seu CPF</ion-label>
      <ion-input name="cpf" type="text" #cpf></ion-input>
    </ion-item>

    <ion-row class="ion-padding-top">
      <ion-col>
        <ion-button type="button" expand="block" (click)="validarCPF(cpf.value)">
          Login
        </ion-button>
      </ion-col>
    </ion-row>

  </ion-list>

</form>

cpf.component.ts

import { ValidateService } from '../validate.service'

export class CpfComponent implements OnInit {

  constructor(private _validateService: ValidateService) {}

  validarCPF(cpf) {
    this._validateService.validar(cpf)
  }
}

validate.service.ts

import { environment } from '../../../environments/environment'

interface respostaAluno {
  ALUNO_ACADEMIA: any;
}

export class ValidateService {

  constructor(private http: HttpClient) { }

  alunoInfo: any = {
    registros: "",
    idAcademia: "",
    nomeAcademia: "",
    idAluno: "",
    idAlunoAcademia: "",
    nomeAluno: "",
    alunoSenha: ""
  };

  validar(cpf) {

    this.receberAluno(cpf)

    if(this.alunoInfo.registros > 0) {
      console.log(this.alunoInfo.nomeAluno)

    } else {
      console.log("Not Found")
    }
  }

  receberAluno(cpf) {
    this.http
      .get<respostaAluno>( environment.url + environment.token + "&Metodo=alunoCheckCPF&AlunoCPF=" + cpf)
      .subscribe(response => {
        this.alunoInfo.registros = response.ALUNO_ACADEMIA.Registros
        this.alunoInfo.idAcademia = response.ALUNO_ACADEMIA.AlunoDados[0].id_academia
        this.alunoInfo.nomeAcademia = response.ALUNO_ACADEMIA.AlunoDados[0].academia_nome
        this.alunoInfo.idAluno = response.ALUNO_ACADEMIA.AlunoDados[0].id_aluno_main
        this.alunoInfo.idAlunoAcademia = response.ALUNO_ACADEMIA.AlunoDados[0].id_aluno_academia
        this.alunoInfo.nomeAluno = response.ALUNO_ACADEMIA.AlunoDados[0].nome_aluno
      });
  }
}

但是我在响应延迟方面存在问题。我输入了有效的CPF，应该在控制台中进行打印：

“法拉利亚·桑托斯（Aline Faria Santos）”

但是印

“未找到”

因为函数validatear（）接收用户的信息，但是当它运行if（）来检查用户是否存在时，注册信息的数量尚未到达要检查的变量，因此当用户不返回时返回给我存在，仅当我第二次单击按钮以打印名称时，该如何解决？
我该如何对已将值分配给变量的函数仅运行IF？请帮我！！