Intrusive thoughts are absolutely normal, not a sign of OCD. If you struggle letting them go, and end up unable to stop trying to reassure yourself, thats OCD.
If its early on, and you are ok with them, just accept them as totally normal. Everyone has all kinds of crazy thoughts, some of them blasphemous, violent, sexually inappropriate. People just have these thoughts, they are a product of a human mind, its part of the condition of being human, its outside your control.
Acceptance, is the best bet at this point, dont actively fight them!