Assistance with HP/Hit Dice

[hgttg42]

Hello everyone, I'm a (to modify a colloquial) long time reader, first time poster.

I've been playing D&D [Edit: 3.5] now for a couple months and have the hang of all but one thing: Hit Dice and HP. (The books are rarely expansive enough imho.) I've asked my group for help on this quite a bit but can't put it down to memory, so hopefully this will get it in writing.

It's fairly simple I know (1 Hit Die + CON mod/lvl)
My problem however lies in the fact that my Hit Dice and CON keep changing, and I don't know how to recalculate.

Here's the rundown:
Started as Doppelganger (4d8 LA +4) ECL=8
Was given half-dragon template (LA +3) ECL=11
Arena leveled me really quickly, now at Fighter 2/Rogue 6 ECL=19
All told, now have 4d12 CON mod = 10 And we are playing full HP every level.

I'm having trouble determining how this plays out. Do LA's affect HP totals etc? If or if not what's my current HP? If someone could please show me how this is done I would be appreciative.

[Vhaidara]

Okay, you have
4d12 Racial Hit Dice = 48
2d10 Fighter Hit Dice = 20
6d6 Rogue Hit Dice = 36
For a total of 12 Hit Dice and 104 HP
You HP is 104 + 12*Con Mod.

LA does not provide any HP. That's part of why it becomes so crippling in large amounts like yours.

[hgttg42]

Makes a lot more sense now, thank you.