Had lochia for 5 weeks after birth & stopped . starts bright red bleeding again in 6th week but not heavy. is this 1st period?

Quite likely: If you are breastfeeding, however, then you may also have some cramping and bleeding, and that could delay your period for up to 6 months.

May be: Lochia is normal for upto 6 weeks post delivery. Your hormones are usually suppressed by breast feeding (BF) after 6 weeks, if you are not BF or if you space out BF, you cud have a normal period - looks more red compared to your lochia.