Is orgasming safe during pregnancy?

I spotted when I orgasmed at about 5+6. I went to the doctor the day after, and things looked normal. I orgasmed again about 3 weeks later, no spotting. I had another US and tests after the week of the orgasm, and everything was great. I orgasmed again today, and so far so good. It happened only a little while ago. A nurse advised me that if I'm not spotting, sex, orgasming, and walking are fine. I don't know. I'm a FTM, so very nervous as is normal. I'd appreciate any personal experience, and any advice and knowledge.