Period Cramps or Pregnancy sign?

Me and my partner have been TTC for 5 months now.

This month my ovulation tests said I ovulated on the 30th March. I usually start to get period cramps around 5 days before my period starts.

My period starts tomorrow and has just started getting cramps tonight. I was hopeful until now but could this be period cramps or an early pregnancy sign?

** we already have a child and conceived extremely quickly with our last so this has been very difficult on us when trying this time**