Are pregnancy scans safe or do they give off radiation ? Is this why nhs only give a 12 week scan and 20 week scan?

I’ve had a scan at 9w4d , 12w4d, 14w1d and would like one at 15w6d for Valentine’s Day (private are open in uk) and my gender scan at 16w5d then my 20week nhs scan is this to much scans ? Are they to close together? Are there risks having many scans?