Early pregnancy symptoms

Ok, so I'm 5DPO and had a miscarriage 6 weeks ago. Since last night I've had mild nausea, tummy cramps, and gas (burping) and some constipation and last night I slept for 10 hours which NEVER happens! I'm a 7 hour a night girl max! I've heard that some people can get early signs from as little as 3DPO and for those who've recently miscarried the body can remember the hormone and pick it up faster?? I'm probably over thinking but I'm desperate to believe this might be true! Has anyone else ever experienced or heard of this and if so, how early did it start? Thanks girls!