Red rash

Has anyone experienced a red rash all over their body? The first one came on at about 7 weeks and we thought it was the detergent, so we re washed everything with a free and clear detergent and it was clearing up. Then Saturday it popped back up again, but much much worse. My fertility doc thinks it might be a reaction to the progesterone injections and doesn't seem super concerned as I am done with those on Tuesday. I'm just worried it's something serious. I see my ob on Tuesday as well so I plan to ask him. Just curious if I'm the only one. I'm 9w 5d with twins, first pregnancy. Thanks