[Tomisimo]

If you want a few more options, just for comparison, here you go.

A pesar de que esto sea correcto...
Even though this is correct... (this is the best, most common way of saying it, as poli mentioned)
In spite of this being correct...
In spite of the fact that this is correct...

Si hubieras estado atento en clase, entenderías el ejercicio.
If you had paid attention in class, you would understand the exercise.
If you'd (you had) paid attention in class, you'd (you had) understand the exercise.
If you had been attentive in classe, you'd understand the exercise.

Que esté aquí ahora no quiere decir que haya vuelto para quedarme.
The fact that I'm here now doesn't mean I'm (I am) back to stay.
The fact that I'm here now doesn't mean I've (I have) come back to stay.
Even though I'm here now, that doesn't mean I'm here to stay. (this is the use of "even though" as Poli mentioned)

Si estuvieras en mi lugar lo entenderías.
If you were in my shoes you'd (you would) understand. (in this case, you use "were" which actually is subjunctive in English).
If you were in my position/place you would understand.