Understanding the gravitational wave emission produced by core collapse supernovae will be essential for their detection in data from current and future gravitational wave detectors. Many current 3D models do not reach far into the explosion phase where gravitational wave emission is expected to peak after the revival of the stalled shock, or are produced from non-exploding models resulting in artificially weak gravitational wave emission. We present gravitational wave emission up to 0.9\,s after core bounce from successful explosions produced with the neutrino hydrodynamics code CoCoNuT-FMT. Different from previous 3D simulations with CoCoNuT-FMT, we simulate in 3D down to the innermost 10\,km to include the proto-neutron star (PNS) convection zone and impose spherical symmetry inside this radius. We include updated neutrino rates and implement on-the-fly extraction of the gravitational wave emission with fine temporal sampling. For the first time, we produce gravitational emission from the explosion of an ultra-stripped star. The ultra-stripped model is simulated from a star with an initial helium star of mass 3.5 solar masses. The second model is a progenitor with a zero age main sequence (ZAMS) mass of 18 solar masses.